2025/11/10

OSR: OD&D Session 1: The Ring and the Marmot

Running a vintage RPG is like running a vintage car. It's fun, but it'll make you realize how much you miss power steering, disc brakes, and seatbelts.

The GLOG is like a handbuilt hot rod. It does its job well, but is more of a heap of loosely linked hopes than a practical everyday vehicle. But you built it yourself and you know what it can do... what will  make the crankcase turn into a cloud of tinsel and smoke. The mutant AD&D version I use for testing is like a rusty station wagon. It still runs, but every part has been replaced at some point, and you wouldn't sell it to a friend. 

Running OD&D is like driving a Model T Ford. It's possible, and it's entertaining, but it's also a bit stressful. I decided to run a by-the-book OD&D game. No initial worldbuilding beyond what's in the books. No outside knowledge of Lord of the Rings or Three Hearts and Three Lions. No Greyhawk, no Strategic Review, just the 3 Little Brown Books, some dice, and some guesswork.

Wikipedia

The Setting

I cover more details about the implied OD&D-derived setting of this game in this post, but this was the pitch the players heard:

The Sai Empire is slowly emerging from a period of civil war. Fabled kingdoms and distant lands that used to send tribute to the capital slipped into independence and myth. The lands beyond the Western Desert are unmapped, untamed, and, so it is claimed, rich beyond belief.

Soldiers of disgraced warlords, drifters, criminals, dreamers, and adventurers are trickling across the desert. Most die. The wilderness is incredibly dangerous. An eagle the size of an elephant carried off a cart and two horses. Giant worms rumble under the surface. Elves stalk the forests. 

But if you survive, and if you prosper, you can be anything. Found a kingdom, a dynasty, an empire. Get rich. Discover world-bending magic. Just watch out for the storm giants, bandits, dragons, and undead.  

The PCs 

  • Gorgontooth the Unslain, Dwarf. Plate armour, shield, helmet, battleaxe. Wishes to become a famous hero. Seems not to understand that "unslain" is the bare minimum qualification.
  • Elizabeth Greenslade, Magic-User. Scribe to Gorgontooth, recording his heroic story. Her Sleep spell is possibly just Elizabeth reading her draft.
  • Chad Bloodsworth, Fighting Man. Plate, sword and shield, rope, and mild paranoia.
  • Lurp, Hobbit. Chad's squire, acquired during the wars. Plate, sling, and spear. A reformed Hobgoblin. 
  • Tim Eonwalker, Magic-User. Disreputable seller of fake potions and false prophecies.  
  • Alcone Darkwell, Cleric (Chaos). Tim's accountant. 
  • Jacob Tallerand, Cleric (Chaos). Anxious spotty teenager. Was on a tomb-robbing expedition. Tried to raise their friend from the dead with a scroll. It wasn't a scroll of Resurrection.
  • Opum, Skeleton. Jacob's friend. Bow and arrow and 2 HP. 

Every player brought at least one interesting twist to their PCs. We learned that Hobbits are reformed Hobgoblins and that they were involved in the civil wars of the Sai Empire. There's a line between too silly. "I want to play a barbarian named 'Arnold Baconandegger' and everything I say is a quote from a movie" is, usually, too silly. "My cleric is an accountant, and my magic-user is their disreputable client" is the perfect amount of silly. It helped establish that the Sai empire has banking clerics.

If Opum survives, as the text suggests, they'll level up to a 2 HD Ghoul, a 3 HD Wight, etc. I ruled that Opum had to use the Skeleton stat block and couldn't wear armour, making them exceedingly vulnerable, but with the usual Undead benefits.    

The OD&D character sheet I'm using. Based on the timeless sheet by Dyson Logos.
 

The Adventure

Arg-e Bam, from The Desert of the Tartars (1977)

After a long and perilous journey through the Western Desert, the PCs reached Fortress Vallat, the last outpost of the Sai Empire. A heap of mud and stone in the desert, inhabited by around 100 flea-bitten and worried soldiers, the fortress felt precarious. It flew a dragon-kite, a construction of wicker, silk, and mirrors designed to warn any nearby dragons that the fortress' light catapults were armed and ready, but the soldiers rarely ventured far from its walls.

With their knowledge of Imperial paperwork and their air of scholarly superiority making the soldiers more talkative, and Tim and Alcone learned of a recent bandit attack. Everyone knew the bandits were hiding in an old tomb in the foothills, but the fortress couldn't spare the forces for a proper reprisal. Anyone who did so would earn the thanks of Ho Tjatbosk, the local Imperial governor (whose territory extended no further than a catapult shot from the fortress' walls), as well as all the bandit loot they could carry.

The PCs had bonded by their journey. Seeing that the fortress was not a source of instant wealth, they decided to take on the bandits.

07.05: Fortress Vallat
08.05 Bandit Camp

With the aid of a sketched map and some Dwarven stone-sense, the PCs were able to locate the entrance to the tomb without too much trouble. 

Fighting bandits underground seemed like a bad idea, so the PCs decided to camp on the hill above the tomb's entrance. Anyone leaving it would be clearly visible, could be attacked from above, and would have to climb a steep hill to reach the group.

Side Note: this was the first "Wow, that's a good plan." moment of the game. I hadn't expected the PCs to simply wait for the bandits to split their forces.  
As the sun set, a group of 16 bandits emerged from the tomb. Before the PCs could attack them, the large rock next to the tomb's entrance shook itself awake. Jaws slavering and eyes flashing, a two-headed Hydra attacked the bandits with ravenous hunger.  
Side Note: The Hydra was the first successful random encounter roll of the session. OD&D's wilderness is deadly. If the PCs had run into it, it probably would have killed them all. Instead, one problem solved another. Lucky PCs; unlucky bandits. I described it as a two-headed hydra because my brain misfired, but I used the stats and HP of a six-headed hydra. I think I interpreted the roll as "d8 heads", not "4+1d8 heads". 

The Hydra attacked, snapping and devouring several bandits. The bandits, in turn, were either unable to hit the lizard or unable to deal critical damage. After a failed Morale test, the handful of survivors fled into the tomb, pursued by a badly wounded but still angry Hydra.

Wikipedia

The PCs cautiously descended to loot the bodies, when a sudden swarm of eight feral hogs emerged from the tomb's entrance. They ran through the group, nearly striking several PCs, and fled oinking into the night.

Side Note: I rolled attacks for the boars, but somehow they all missed. As you'll see later, my dice favoured the PCs this session. This was another knock-on effect of the random Hydra encounter; it cleared a room and some potential enemies. 

After waiting a few minutes, the PCs descended into the tomb. In another sensible decision, they decided to immediately track down and finish off the wounded Hydra. They descended the stairs (1), ignored three metal doors (4,5,6) and a side passage, and followed the trail of Hydra blood and mangled bandits to another set of stairs (7).

As they descended, the Hydra charged, its one remaining head snapping at Gorgontooth the Unslain. Luckily, Opum the Skeleton fired an arrow into the Hydra's open mouth, smashing its brain just as its fangs closed around Gorgontooth's torso.

Side Note: Initiative in OD&D is rolled on 2d6. The Hydra had 10; Opum got 11, hit, and dealt 4 damage. The Hydra had exactly 4 HP remaining. We got the Initiative sequence slightly wrong, so the attack against Gorgontooth - which would  have nearly killed the Dwarf - was rewound. It was the closest possible shave.

Chad Bloodsworth burnt the Hydra, to prevent its heads from regrowing. The PCs decided to explore a few rooms before returning to the first level. A room to the south (12) contained a mysterious well. A room to the west contained a small pile of gold... which the PCs found suspicious. Lurp the Hobbit threw a rock at it, revealing the gold to be real gold, but surrounded by a carpet of centipedes!

With the aid of some lamp oil and a torch, the PCs burned the swarm before it reached them. Alcone Darkwell, Cleric/Accountant, started to have regrets about this new tomb-robbing lifestyle. 

The PCs bagged the gold, as well as mysterious wooden staff under the debris. It looked magical, so Tim Eonwalker grabbed it, but couldn't figure out how to activate it.

Side Note: A randomly generated Staff of Control Plants was, perhaps, not the most useful item to find in a plant-free dungeon, but that's how random generation goes.

They returned to the first level and opened the three metal doors (7,8,9), revealing only magical darkness beyond. The PCs briefly debated sending someone in with a rope tied around their waist, but nobody volunteered. 

As they continued to explore, another swarm of centipedes - perhaps disturbed by the firey demise of their brethren on the 2nd level - emerged from cracks in the stone. The PCs dealt with them quickly with oil and torches.

Side Note: This was the only successful random encounter roll so far, and centipedes - though potentially deadly - are still one of the better options on the OD&D random encounter table. It's possible for PCs on level 1 to run into 2d8 4 HD level-draining immune-to-non-magical-weapons Wraiths! 

The PCs found a few more gold pieces and another dead bandit in the pigsty (2), and some spare torches in an empty room (8). They also discovered a fountain (3), with a statue of a robed figure holding a book. Gorgontooth the Unslain guessed that it was sculpted by magic, and that the water was also probably magical. Several PCs took a drink, but the Chaotic clerics sensibly declined.

Side Note: The fountain cast Bless on Lawful characters (only Lurp the Hobbit), healed Lawful and Neutral characters for 1d6, and dealt 1d6 damage to Chaotic characters. Luckily, Lurp went first, and seeing the results none of the Chaotic characters risked it.

Also, I couldn't remember the term "pigsty." My brain came up with "piggery", to much merriment.

The party descended once again. They explored a storeroom (14) and stocked up on rations, spotted a staircase (15) but did not approach it, then found a bandit encampment at the end of a hall (23).  The bandits that would have occupied the bedrolls and tables were scattered around the dungeon thanks to the Hydra. 

The PCs heard faint music from the door to the west (23) and guessed that a few more bandits must be inside; more than 2 (judging by the three-part harmony) but less than 100 (judging by the room size). 

Chad Bloodsworth decided lure one out. Some oddly convincing cries for help attracted one bandit. Lurp and Chad grabbed him, but, as both were clad in plate armour, made an unholy racket. A brief and confusing interrogation, they determined that "around 20" bandits were on the other side of the door. 

The singing continued from inside the room, but in a slightly strained way, as if one singer was trying their best to cover up the sound of martial preparation.

The PCs prepared a very cunning plan. They assembled in front of the door, plate and shield fighters first, then kicked it open. Thirteen bow-armed bandits, with one higher-level leader, stared back at them. Before arrows could fly, Tim Eonwalker cast Charm Person on the bandit leader, unsuccessfully. Elizabeth Greenslade cast Sleep on the bandits, successfully knocking out nine of them. Lurp stunned one of the awake bandits with a rock. Suddenly outnumbered, the bandits immediately surrendered. 

Side Note: The plan was very risky and relied on good initiative rolls (or a 2-in-6 surprise check), but Sleep was practically guaranteed to take out a large number of bandits. It's a pity Charm Person didn't work, because a Level 4 Fighting Man would have made a mighty hireling, but it was a good attempt. 

The PCs forced the bandits to reveal their loot, acquiring two 2,000gp diamonds and a 6,000gp piece of jewellery; a decorative cityscape intended as a gift for the Orc city of Vardovarri. They also released the bandits' prisoner. The Orc warrior Kchut explained the whole situation to Lurp, as they both spoke goblin, and none of the bandits did. Gorgontooth listened in.

The bandits, Kchut related, had a famous leader called "The Marmot", who claimed to have a plan to conquer Fortress Vallat with the aid of a magic ring. While exploring down the well (12), the Marmot apparently perished. Dashtar, the current bandit leader, took over. The bandits are all afraid of a "cat-monster" somewhere else in the dungeon, and roast unhelpful prisoners using the fire pit traps to the south of the barracks (23).

The PCs openly debated executing everyone, or leading them back to Fortress Vallat, or throwing in with the bandits and forming a raiding crew of their own. They eventually decided to disarm the sleeping bandits, tie up the others, and lead them through the dungeon as mobile trap-finders. Chad Bloodsworth agreed to take on Kchut the Orc as a hireling. 

When the group approached the third staircase (15), the bandit leader Dashtar kicked one of the tied bandits down the stairs, then turned to run. The stairs turned into a greasy ramp, sending the restrained bandit tumbling into darkness. A spine-chilling roar shook the dungeon.

"The beast!" Dashtar cried, scrambling to escape. Chad Bloodsworth and Lurp tackle the bandit, while the rest of the group left the plate-armoured fighters behind in headlong flight. The hideous shaggy head of a Manticore emerged from the stairs, turned to look at the group, and swung its deadly spiked tail up the hallway.

Six manticore spikes shot outwards.  Six spikes struck home. All six rolled 1 damage each.

Baffled at their luck, Chad and Lurp dragged Dashtar around the corner, and the Manticore retreated to its lair to feast. 

The group debated retreating from the dungeon and splitting their wealth, but, buoyed by the lack of random encounter rolls, their new hirelings (voluntary and otherwise), and the prospect of a powerful magic ring, they decided to continue.

They came up with an excellent plan to explore the well (12). They threw down torches until the cavern was partially illuminated, then lowered the lightly restrained bandits on ropes, and then threw down weapons.

The 12 HP Giant Leech in the pool, as well as the Zombified corpses of five unlucky bandits, quickly overcame the four bandits and Dashtar. Opum the Skeleton, with tireless accuracy, leaned down the well and shot arrows at the survivors until the room seemed safe. The had plenty of arrows to waste; they took every arrow from the bandit encampment and heaped them around the well.

The PCs used all their remaining rope to build a sturdy ladder system, then descended into the cavern (25). Jacob Tallerand went first, and immediately started searching for the Marmot's corpse and its fabled ring. Heedless of danger, Jacob sprinted into a side cavern (26), found a body with a glowing fire opal ring, cut off the corpse's finger, and slipped the ring on.

Side Note: I misread my own map and put the Marmot's corpse in (26) and not (30), but so it goes.  

A flash of fire lit up the cavern, as a 8' tall being of smokeless flame emerged from the ring. "I am the servant of the ring," it intoned. "What is your will, o master?"

Jacob's eyes lit up. "Bring me a scroll of Raise Dead!" he cried. 

"This is within my power," the Djinni said, and vanished in a blast of flame. A few moments later, a scroll appeared before the startled cleric.

Side Note: Yes, technically Djinn in OD&D can't grant wishes or make scrolls. A cruel GM could  have created an illusionary scroll, but I am not that cruel. It's a real scroll (possibly stolen) but I anticipated a few problems. First, despite the group's luck, I expected that Level 3 of an OD&D dungeon would quickly thin the herd, making the choice of who to raise interesting. Second, the scroll is a fragile scroll, and could easily be damaged or destroyed. Third, raising Opum the Skeleton is Jacob's main goal, and it would conveniently turn a Skeleton (and potential Ghoul, Wight, etc.) into merely a Level 1 Fighting Man. 

"Yes!" Jacob shouted.

"What was that?" the rest of the group inquired from a safe distance. "Did you find the Marmot's body?"

"Uh, no, this was an unrelated thing," Jacob quickly lied, rubbing the ring again. 

The Djinni reappeared with a whoosh. "What is thy bidding, my master?"

"There's a Manticore in this dungeon. Go fight it," Jacob said excitedly, pointing vaguely in the right direction. The Djinni flew off like a comet.

It returned a few minutes later, with several ragged holes in it's burning torso. "I fucked up, o master," it said. "It's too strong. Ooow. Ooooowww..." It sank slowly into the ring, until only a pained face was visible on the gem's surface. 

Side Note: Run the numbers. A Djinni is a 7+1 HD creature (rolled 19 HP), AC 5, dealing 2d6-1 damage. The Manticore is a 6+1 HD creature (rolled 16 HP), AC 4, dealing 1d6 damage... and capable of firing 6 1d6 crossbow shots at once. The Djinni hits the Manticore on a 9+ (1x0.6x6=4.2 average damage. The Manticore's tail attacks hits the Djinni on an 8+, with a +1 bonus for close range. (6x0.7x3.5 = 14.7 average damage). The rolled damage worked out more-or-less the same, except that the Djinni didn't even get a hit off before taking serious damage and fleeing. 

"So we've got a weak Djinni," Chad Bloodsworth said. "Fantastic. Didn't the Marmot want to take on Fortress Vallat with this ring?"

"Maybe he wasn't very smart. I mean, he did die to a giant leech," Alcone Darkwell replied.

Gorgontooth the Unslain searched the leech's watery pit for treasure, finding a few more coins and not catching any leechborne diseases.

"My flesh is clay," he explained. "That's how Dwarves are."

Side Note: That's how dwarves are in this setting, I guess. Dwarves are made of clay, Hobbits are reformed Hobgoblins, and everyone is scared of Elves for reasons we have yet to determine.

The party ventured north (27), but entered a cave with a quicksand floor. Jacob Tallerand, Tim Eonwalker, and Alcone Darkwell started to sink, but quick work with ropes and spears pulled them out before they vanished forever. The party skirted the edge of the sand and proceeded west (28).

The slate floor of the cave was trapped. Thin plates of stone rested on a grid of thicker supports, above a 30' deep pit of spikes. 

Elizabeth Greenslade discovered the trap when the group was halfway across the room. She did not survive the fall.

The group froze. A wrong step in any direction could be deadly. As they debated their next move, two ash-streaked robed figures came around the corner, raised their hands, and cast spells at the PCs.

Side Note: The encounter I rolled was "Evil Priests", and an undiscovered room to the north contained two Evil Priests, so it made sense for them to be attracted by the noise and ambush the party while they tried to navigate the pit traps.

The first Evil Cleric a Reversed Cure Wounds spell on Tim Eonwalker, dealing a whopping 3 damage, which was enough to kill the 2 HP Magic-User. The second Evil Cleric cast Hold Person on Chad Bloodsworth, Lurp, and Kchut the Orc. Lurp passed his Save; the others failed. 

"Attack your frieeeeends," the Evil Cleric commanded.

"None of these people are my friends," Chad argued. It was true. At Fortress Vallat, Chad had carefully explained that the shared bond of travelling did not approach friendship, and that Lurp was his squire, not his friend. 

"Yeah, I just met these people," Kchut said. "I'd barely call them acquaintances. The only person who I'd say is close to a friend is Chad, and you just mind controlled him."

This brilliant telepathic argument gave the group time to act. Alcone Darkwell ran west, safely avoiding the pit traps, but pursued by the mind-controlled Chad and Kchut. Gorgontooth and Lurp opened fire with thrown stones and daggers, lightly wounding one Cleric.

One Evil Cleric used Turn Undead, sending Opum the Skeleton fleeing west. Both Evil Clerics then retreated around the corner, out of line of sight. They apparently hoped the mind-controlled Chad and Kchut, along with the pit traps, would weaken the rest of the party.

Side Note: I forgot that Evil Clerics can't cast Turn Undead. Maybe they were... Good Evil Clerics? Oh well.

Jacob Tallerand decided to leap forward, hopefully avoiding the traps, but failed. The slate floor split under the spotty cleric, and he plunged his death.

With slightly more caution, and some judicious arguing over the wording of the Dwarf's trap-finding abilities, Gorgontooth the Unslain and Lurp the Hobbit charged the two Evil Clerics. Gorgontooth slew one, ending the Hold Person spell before the mind-controlled PCs could make their attacks. In return, the other Cleric brained Lurp with a mace. The valiant Hobbit fell.

Gorgontooth the Unslain, with a whopping 7 HP, fought the remaining Evil Cleric for several rounds. He even had time to take a swig from his wineskin full of fountain water, restoring 3 HP. 

Up the corridor, Alcone Darkwell and Opum the Skeleton opened a sliding stone door, revealing a red metal door (33). They opened this door, revealing three Minotaurs with enormous axes. Alcone screamed, slammed the door closed, and ran east.

Side Note: I could have had the Minotaurs pursue, but the comic timing was too good. 

Gorgontooth finally managed to slice the second Evil Cleric in half, then returned to reveal the safe path across the pit trap room. 

With four of the eight starting PCs dead, and some excellent treasure at the bottom of a 30' spiked pit, how will the party proceed? What else lurks on Level 3 of this dungeon? Will the survivors retreat, level up, and return, or cut their losses and flee immediately? 

Wikipedia

Prep & Final Notes

Pre-session chatting, character generation, and dinner took about 1 hour, which isn't too bad. 
I could have done a better job explaining AC and the to-hit-AC values. 

3d6 down-the-line stats produced some mixed characters, but stats don't matter much in OD&D. 

I printed off a quick-reference inventory + weight page, which really sped up the gear buying process.

I had two copies of Greyharp's One Volume OD&D rules printed for the table, but I think a game like this works best if everyone has a copy of the rulebook(s). For future games, I'll print off some more. 

Lurp the Hobbit can't be revived by the scroll of Raise Dead (it's Men, Elves, and Dwarves only). But they could be Reincarnated. Hobbits cannot enter Heaven and are trapped in the cycle of samsara. 

OD&D is not a difficult system to run by the book, but it does make you miss all the little houserules, modifications, and shared wisdom (or shared foolishness) that modern-ish OSR games include.

Item-based problem solving was a highlight.  

Everyone agreed that mapping was tedious and slowed down the game without adding much of value. I tried to include several Gygaxian map tricks in this dungeon, but they didn't lead to interesting gameplay (at least compared to other types of gameplay). The mapper had to switch focus constantly, I had to remember to read out room sizes and try to describe entrance and exit locations, etc. For future sessions, I'll go back to my usual methods of revealing a pre-printed map.  

The entire session (including character generation and dinner) took 5 hours. I think that's a pretty decent pace of play, especially with two novice players.

2025/10/27

OSR: Treasure Curves & Generation Procedures

Work continues on the Treasure Overhaul, and that means math.

Part 1: Gem and Jewellery Generation

The book will include treasure tables, so I've spent quite a bit of time digging into their function, their challenges, and their deceptive math.

Treasure Type A is bandit treasure. Sure, in AD&D it's also associated with the Lich, Locathah, Troglodytes, and the Giant Squid, but it is, in most system that include treasure tables, A is "the chest at the heart of the encampment" treasure. It's a useful point of comparison. We'll ignore coins and magic items for the time being.

OD&D: 50% chance of 6x1d6 gems /  50% chance of 6x1d6 pieces of jewellery
AD&D: 60% chance of 4x1d10 gems / 60% chance of 4x1d10 pieces of jewellery
OSE:  50% chance of 6d6 gems /  50% chance of 6d6 pieces of jewellery*
TO: 50% chance of 6d6 gems /  50% chance of 6d6 pieces of jewellery*

*The average of 6d6 and 6x1d6 is the same: 21, but the distribution changes significantly. OSE's treasure results fall in the middle of a curve instead of spreading out. 

 Yanping Wang, Sand

Gem Procedure

I started with:

For each gem or batch of 5 or 10 gems: 
1d20
1-4: 10gp
5-9: 50gp
10-14: 100gp
15-18: 500gp
19: 1,000gp
20: 5,000gp

For each gem or batch with a roll of 15+, roll an additional d20. 
1-16: No effect
17-19: x2
20: x10

This procedure looks good. It passes the back-of-a-napkin math test. But it doesn't pass the complicated math test. 

When simulated, the results look like this:


I've charted them alongside OD&D, AD&D, and OSE's gem results for Type A treasure.OSE has a small gem value table and no way to increase a rolled value. It's tidy, but it's flat. 

You can see that the Treasure Overhaul's results spike way higher than the reference systems. Around 15% of results are above 20,000. The general shape looks OK, and the lower end of the range lines up nicely, but it clearly needs some tweaks. 

After some guesswork and tests, the revised procedure looks like this:

For each gem or batch of 5 or 10 gems:
1d20
1-4: 10gp
5-9: 50gp
10-14: 100gp
15-18: 500gp
19: 1,000gp
20: 2,000gp

For each result of 15+, roll an additional d20. 
1-16: No effect
17-19: x2
20: x3

Tweaking the top of the modifier table to x4 results in an overshot. I could fiddle around with the 19 and 20 results on the main table to get the perfect top-of-the-range match, but that pushes the centre of the curve away from OD&D and A&D.

This method does not have a chance to produce extremely high-value gems, unlike OD&D/AD&D's recursive lottery, but it's a surprisingly close match, and it only requires 2 rolls (or one throw). Gem values are capped at 6,000gp, which is plenty for spell purposes (especially in a batch of 10), and the GM is free to combine gems.

I wanted to keep 6 possible outcomes on the d20 table so that each outcome is associated with a different tier of stone, or with one emblematic D&D / spell component stone.


TO Gems (Original) TO Gems (Revised) OD&D Gems A AD&D Gems A OSE Gems A
Average: 4,542gp 3,405gp 3,243gp 3,765gp 2,208gp
>3x Avg: 7% 12% 10% 0% 8%
>2x Avg: 11% 17% 14% 17% 24%
# of Gems Avg 10.5 10.5 10.5 15 10.5
Gem Avg. 433gp 324gp 309gp 251gp 210gp


This gem procedure is fairly elegant; you just roll 2 d20s at once and only reference the second one if the first is 15+. I even made the gem type/description tables d12s and d6s, so you can roll a d12 and a d6 in the same handful and get all the results you could possibly need at once, without interference. I could have used a d100 instead of one of the d20s, but testing confirmed that d100 rolls are annoying for batched results.

Censer c.~1500

Jewellery Procedure

As mentioned in my previous post, jewellery is the meat-and-potatoes of OD&D and AD&D treasure table results. 

I started with:

For each gem or batch of 5 or 10 pieces of jewellery: 
1d20
1-5: 200x1d10gp
6-14: 500x1d10gp
15-20: 1000x1d10gp

For each result of 15+, roll an additional d20. 
1-16: No effect
17-19: x2
20: x10 x3

I'd like to use the same modifier table for both Gems and Jewellery, the so table was adjusted accordingly. It turned out to be exactly what the Jewellery table required. I ran a few tests with tweaked values, but it turns out that the results are nearly perfect as-is, post gem revision.

I'll continue to test this system, just in case the highest value needs to be tweaked from 1,000gp to 900gp, but so far the results are very encouraging.

 

TO Jewellery A OD&D A AD&D A OSE A
Average: 35,524gp 32,858gp 35,902gp 9,342gp
>3x Avg: 10% 9% 10% 4%
>2x Avg: 25% 23% 19% 26%
# of Pieces Avg 10.5 10.5 13.2 10.5
gp/Piece Avg 3,383gp 3,129gp 2,720gp 8,90gp
 

Part 2: OD&D Treasure Comparisons

Here's a comparison of all the major OD&D treasure types. 200 runs each.


I wish OD&D named its treasure types instead of vaguely implying their function, but, thanks to this chart, some of the principles become more clear. Courtney Campbell broke down the AD&D charts here. Here's my take on OD&D. They're not as baffling they first seem.

A is Men (non-nautical, non-desert) and Centaurs. It's a Bandit Lair / Treasury

B is Ghouls, Wights, Hydras, and Nixies. Things that kill adventurers by the dozen. It's Loot / Burrow / Gullet items. The magic items are "Weapon, Armour, or Misc. Weapon." Presumably they didn't work.

C is Gargoyles, Lycanthropes, Minotaurs, Pixies, Gnomes, and Ogres. Ogres add +1,000gp. It's Pocket Change. If it doesn't include jewellery (a 75% chance) it's basically worthless.

D is Orcs, Hobgoblins, Gnolls, Trolls, Mummies, Cockatrices, Manticores, Purple Wurms, and Dryads. I'm calling this Traders and Raiders. Portable, practical wealth.

E is Wraiths, Spectres, Gorgons, Wyverns, Elves, Griffons, and Giants. Giants add +5,000gp. It's Better Pocket Change. I'm not totally sold on this as a unique treasure type. More magic items than C, but otherwise, it's just C + gold pieces + better chances.

F is Vampires, Basilisks, Meduae, and Chimeras. It is heavily jewellery-weighted, with 2-24 pieces. and the magic items stipulate "no weapons". This is Glittering Trinkets. Even an immortal vampire eventually gets tired of being stabbed by decorative mantlepiece swords.  

G is Dwarves. Gold and magic items. It's a Dwarven Trove. There's nothing else it could be. Gold, more gems than jewellery, and a good chance of magic items. You can clearly see the steps of the 1d4x10x1,000gp in the blue coin section.

H is Dragons. It's a Hoard. Lots of everything, but (as previously discussed) more gems and jewellery than coins. 

is Rocs. It's Shiny Things. Jewellery and gems only; stuff a magpie the size of an elephant would loot.

Some of the categories still don't make any sense to me. Why do Griffons get scrolls? Why aren't weapons scattered around a Basilisk, and why do Chimeras need all that jewellery? But despite a few oddities, these charts really helped me get a grip on OD&D's internal logic. AD&D is... another matter.  

Final Notes

I hope this offers some insight into the rigorous (and peculiar) methods that are applied behind the scenes of the Treasure Overhaul. There are plenty of things that I'm happy to eyeball or write from scratch, but if I'm going to include treasure tables, I want them to be as sturdy as possible.   

EDIT: One potential reason why a lot of calculated average values for OD&D Treasure Type A (or conversions based on it) online and my values are so different might lie in the deceitful 6d6 vs 6x1d6 roll. 6d6 and 6x1d6 have the same average of 21... but think about the distribution. The chance of rolling a 36 on 6d6 is 0.2%. The chance of rolling 36 on 6x1d6 is 16.6%. And when we're talking about gems, where each gem can suddenly increase in value... 

2025/10/26

OSR: Testing Treasure Tables & Treasure Values

Treasure tables are, for better or worse, part of old-school RPGs. Since the intention is to make the Treasure Overhaul a very useful and broadly compatible book, it's important to understand the subtleties of historical treasure generation. The average treasure value of a given type is relatively easy to calculate. It's also deceptive. Averages are a good start, but if you only look at averages, you can easily miss the big picture

To make sure I understood the bones of OD&D and AD&D's famous treasure tables, I cobbled together a spreadsheet that runs through 100 at a time. No, you can't see it. It's awful. I'm reasonably confident it's correct, but it's not elegant.


OD&D Treasure Type A1 

Bars are cumulative. 200 trials.

I ran many, many trials to confirm the general trends, but charts with 200 results are easier to read. 

1. Null results

Around 8% of rolls for Type A1 result in 0gp. Around 20% result in less than 1,000gp. 

There's an argument to be made that unexpectedly high-value results (>150,000gp for A1) only feel "real" if there's a chance of unexpectedly low results. I'm still thinking this concept through.

Take random encounter tables. Nobody insists that if a Random Encounter Table includes 3d6 level-draining PC-slaughtering Wights, it's only fair that it include 3d6 helpless Marshmallow Cuddlebugs. The low result isn't required to make the high result feel "worth it". There's usually a spread of results and deadliness, sure, but in OSR games, even a handful of Goblins can be dangerous. People would complain if a random encounter table was 10% empty. 

On the other hand, a random encounter table is only used some of the time. A treasure table is used every time (in theory). So a 0gp treasure is just moving the probabilities of a no-encounter roll to a different step.

A 0gp result can also help with worldbuilding. When I rolled up my OD&D Hexcrawl (available on Patreon) I had a surprising number of 0gp results to explain. That's part of why I created the spreadsheet. I wanted to see if I was unlucky or incompetent. Turns out it was probably both. Hooray!

Antonio J. Manzanedo

2. Gems and Jewellery

The structure of a treasure table, and cultural depictions of dragon hoards, suggests coins are important while gems and jewellery are accessories. The results (and plenty of documented wisdom) shows that this isn't true. Coins are a consolation prize. Gems are a lottery ticket that could boost a small treasure into an enormous one. But the meat-and-potatoes of the OD&D treasure table is jewellery.

Taken from Greyharp's Single Volume Edition.

Treasure Type A1 has a 50% chance of including 3d6 pieces of jewellery. If the treasure includes jewellery, it's all but guaranteed it will dominate the result. You can see the cutoff on the chart.

To match the usual at-table procedure, the sheet rolls jewellery and gem values in batches of 10. E.g. if I rolled a 36 on 6x1d6, I'd roll for 10, 10, 10, and 6 gem values. All you need is one batch of 10 hit 10x1,000gp and you've got 100,000gp. 

To put it another way, for Treasure Type A1, if you roll Jewellery, you get a minimum of 6 pieces. At the minimum value of 300gp per piece, that's 1,800gp. That's worth more than the maximum roll for Copper and Silver coins. The jewellery table is the driving value behind treasure in OD&D. You could leave coins out entirely and barely notice.

Values of each type of treasure, separated. 500 trials.

3. The Gem Lottery 

In OD&D, gems have a base value based on a 1d100 roll, and then a 1-in-6 chance to upgrade to the next highest value (or a list of higher values that can't be initially rolled), up to the incredibly unlikely 500,000gp. Gems are the lottery tickets of the OD&D treasure table. 

But "standard" upgrade, of 10x 1,000gp gems to 10x 5,000gp gems or 10x 10,000gp gems still only puts the Gem results in the midrange of Jewellery results. You can see that on the chart. There are a few results where Gems form the bulk of the treasure, but the solid and consistent mass of Treasure Type A's value comes from Jewellery.

4. Average Value Check

Just to make sure I'm not totally crazy, let's run through some basic averages for OD&D jewellery.

OD&D Jewellery (Type A1) Average Calculation
Roll Value Value Rate Product
20 (3d6x1000) 1050 0.2 210
80 (1d6x1000) 3500 0.6 2100
100 (1d10x1000) 5500 0.2 1100


Average Per Piece




3410


Average Pieces Per Type A1



(6x1d6) 21


Average Per Type A1




71,610
My Calculations (500 runs) Rate 0.5

36,358
Average 35,805

That's pretty darn close, and it matches the values found by others. But this does suggest that Delta's famous XP/GP tables are incorrect, at least for OD&D (if I'm reading them correctly).

OD&D Treasure Type H

Bars are cumulative. 200 trials.

Ah, the classic Hoard. In A1, Gems and Jewellery have same number of pieces (6x1d6). In H, Gems have 1d100 pieces, while Jewellery has 1d4x10 pieces. This provides more-or-less the same jewellery values, with the added boost of a high gem roll giving a higher chance upgrading gem values. In A1, there are at most 4 "batches" that can be upgraded. In H, there are up to 10.   

It's interesting that the top ~20% of Type A1 is above 100,000gp, while ~30% of Type H is above 100,000. Type H feels larger, with its 1d100 gems and 6x1d10x1,000gp, but in practice it's all jewellery-dominated. A has a 50% chance of 6x1d6 pieces; H has a 50% chance of 1d4x10 pieces. The difference between 6x1d6 and 4x1d10 is not terribly significant. 

Dragons, the standard hoarding creatures in OD&D, do have a built-in age-related multiplier. "Very Young and Young Dragons are unlikely to have acquired treasure. Sub-Adult Dragons will have about half the indicated treasure for Dragons. Very Old Dragons can have as much as twice the indicated amount." 

AD&D Treasure Type A 

In AD&D, Treasure Type A is used for for the Lich, Locathah, Men (Bandits), Troglodytes, and the Squid Giant... for some reason. It's a mixed bag.

Bars are cumulative. 200 trials.

As usual, AD&D's procedure is OD&D + a layer of complexity.  

I did not implement the stone increase/decrease base value table. It's more complicated than OD&D's. I looked at it, and I tested out a few worst-case scenarios, but it's a horrible and recursive thing and I just can't be bothered. It provides for a runaway doubling of gem value (as in OD&D) but it's so hard to implement cleanly (with my very limited skillset, at least). As my grandfather said, just before his homemade self-driving car took him over a cliff, there are times when you should code things properly and times when nested IF statements are good enough. 
Jewellery in AD&D also has a runaway increase. If the piece has gems (on a 51+), roll 1d8. On a 1, add 5,000gp and roll 1d6. If that's a 1, double it to 10,000gp and repeat, to a maximum of +640,000gp. There's a craftsmanship value adjustment step which I didn't implement.

The point is to confirm that, in AD&D as well as OD&D, the "average" treasure value doesn't tell the whole story. Jewellery dominates the chart.  

Final Notes

Treasure tables are fun. They are also very difficult to implement with at-table utility in mind. For a pre-generated dungeon, where the GM can sit back, roll, and type things into a calculator, they work just fine. But at the table, with the pressure of game flow bearing down on them, and the added pressure of fast math, they're a slog. 


I've also created a small OD&D hexcrawl and 3-level standard dungeon. They're available on Patreon. I sometimes post previews of the Treasure Overhaul on Bluesky.

2025/05/15

Pulp: Adventure Location: Trindade & Martim Vaz

History is fractally interesting. Start examine any event, or following any citation, and interesting facts emerge. But some places, for whatever reason, seem to attract a disproportionate level of interesting events.

wikipedia

Trindade
is a small volcanic island in the middle of the south Atlantic. 700 miles off the coast of Brazil, and more than 1,200 miles from Ascension Island (itself a tiny volcanic dot in the sea).
The island is around 3.5 miles long and 1.5 miles wide. Despite being a speck of land in the middle of nowhere (or possibly because if it), Trindade has a very high density of RPG-relevant plot seeds. 

Feel free to jump ahead to section 7. It's where the real Call of Cthulhu stuff starts. The rest is useful, but but section 7 is why this article exists.

1. Summary

Here's an official overview of the island, from the South Atlantic Directory via E.F. Knight's, The Cruise of the Falcon.

Trinidad is surrounded by sharp, rugged coral rocks, with an almost continual surge breaking on every part, which renders landing often precarious, and watering frequently impracticable, nor is there a possibility of rendering either certain, for the surf is often incredibly great, and has been seen during a gale at S.W., to break over a bluff which is 200 feet high. 

Captain Edmund Halley, afterwards Dr. Halley, Astronomer Royal, landed on this island, the 17th of April, 1700, and put on it some goats and hogs, and also a pair of guinea fowl, which he carried from St. Helena. 'I took,' says his journal, ' possession of the island in his majesty's name, as knowing it to be granted by the king's letters patent, leaving the Union Jack flying.'

When the English went to Trinidad in 1781, in order to ascertain whether a settlement was practicable there, they did not find it answer their expectations.

The American commander, Amaso Delano, visited Trinidad in 1803, and he, again, describes it as mostly barren, rough pile of rocky mountains. What soil there is on the island he found on the eastern side, where are several sand beaches, above one of which the Portuguese had a settlement.

This settlement was directly above the most northerly sand-beach on the east side of the island, and has the best stream of water on the island running through it.

Delano got his water o£f the south side of the island. Here a stream falls in a cascade over rocks some way up the mountains, so that it can be seen from a boat when passing it. After you have discovered the stream, you can land on a point of rocks just to the westward of the watering-place, and from thence may walk past it, and when a little to the eastward, there is a small cove among the rocks where you mav float your casks off. Wood may be cut on the mountain just above the first landing-place, and you may take it off if you have a small oak boat.
Knight, The Cruise of the Alerte.

2. The Astronomer: Sir Edmund Halley, 1700

Whilest the Long Boate brought more Water on Board I went a Shore and put Some Goats and Hoggs on the Island for breed, as also a pair of Guiney Hens I carry’d from St. Helena.

-Edmund Halley's log for April 17th, 1700, as quoted on Halleys Log.

From a modern ecological perspective, landing "Goats and Hoggs" on an isolated tropical island is slightly better than detonating a thermonuclear warhead on it, but only slightly. But in 1700, ecological preservation was not an issue. Halley lived closer to witch-burnings (1727) than to Charles Darwin. Scurvy, which killed between 20% and 50% of sailors on long voyages (though digging into the source of that number leads to some dubious math), was an issue; the only known cure was fresh food. Rats and cats may have already been present, deposited by prior visitors or shipwrecks.

Plot Seeds for 1700

-Edmund Halley has some tentative ideas on the cyclical nature of comets, and the cyclical nature of the world. The impact of a comet could, by Halley's estimation, churn the world's surface, extinguishing all life and human civilization, which God, in his wisdom, would then renew. Genesis, and biblical history, starts with a comet impact. What happened before is unrecorded. This may explain certain oddities about the age of the solar system, erosion, nutrient depletion, rock formations, etc. It explains why Hudson's Bay is colder than its equivalent latitude in Europe; it's the icy residue of the former North Pole, but the Earth was knocked off its old axis by the last impact. Halley though the most recent impact site was the Caspian Sea, with its crater-like southern basin. Trindade isn't on the opposite side of the world (that'd be too convenient), but Halley expected rings of waves to travel around the world, smashing into each other, burying sea life under newly raised mountains (to produce fossils). A ridge of mountains in the sea, like the Trindade, could validate that theory. A few heretical fragments of an ante-antediluvian civilization could, in theory, be present in such a place. What technological heights did the last people (if they were people) attain, before all Creation returned to Chaos?

-Halley also proposed that the Earth is hollow (ish), although his hypothesis is closer to an "iron core inside a molten shell" than "caverns full of mushrooms and dinosaurs." But it's still a hollow earth proposal, and if your players don't check their references carefully, it'd be easy to pick out a few quotes, put an entrance in Trindade, and set the players on a fun Verne-style adventure. 

-Halley invented an early diving bell, capable of reaching depths up to 20m. Using one near Trindade seems like drowning with extra steps, but a secret 18th-century submarine project could be useful for a secret history game. Sinking Spanish and Portuguese ships in a deniable way, looting undersea treasures, etc.

Fernando Faciole, Discover Wildlife

3. The Survivors: The Wreck of the Rattlesnake, 1781

HMS Rattlesnake, a 198-ton, 12-gun cutter-rigged sloop, was wrecked on Trindade on 21 October 1781, shortly after Commander Philippe d'Auvergne had taken over command. Rattlesnake had been ordered to survey the island to ascertain whether it would make a useful base for outward-bound Indiamen. She anchored, but that evening the wind increased and by seven o’clock she was dragging. Two hours later the first cable parted and Commander d’Auvergne club-hauled his way out, setting main and fore sails, and using the remaining anchor cable as a spring. This successfully put Rattlesnake’s head to seaward. The remaining cable was then cut, and the sloop wore round and stood out to sea. However the ground now shallowed quite rapidly and suddenly Rattlesnake struck a submerged rock. She started filling with water, so, in order to preserve the lives of the crew, d'Auvergne ran her ashore. Commodore Johnstone on board HMS Jupiter had previously wished to colonise the island and claim it for Britain, so d'Auvergne agreed to stay on the tiny island with 30 sailors, 20 captured French sailors, one French woman, some animals and supplies. They were resupplied by another ship in January 1782, then they appear to have been forgotten, as they lived on the tiny island for a year until HMS Bristol and a convoy of Indiamen, which fortuitously called there, rescued them in late December 1782.

-Wikipedia

This seems like an extraordinary story, but there's not much info available online. I've ordered a copy of the wiki article's main source (In the English Service: The Life of Philippe D'Auvergne by Jane Ashelford), and I'll update this article when it arrives (or when I can track down other sources). I have so many questions. Some of them are not pleasant.

That anyone, let alone such a heterogenous crew, could survive fourteen months on Trindade is remarkable. As we'll see, it can't have been easy. Halley's hogs and goats don't seem to feature in the accounts I've found so far.

Plot Seeds for 1781

-Your boss has marooned you, thirty sailors, twenty French sailors, and one French woman on a volcanic island. 

-As above, but after surviving and returning to civilization, you may feel the need to seek poetic revenge.

4. The Sea-Captain: Amasa Delano, 1803

The account of Amasa Delano is utilitarian to the point of brusqueness. He reports "plenty of goats and hogs", which could be survivors of Halley's expedition or new arrivals left by Portuguese settlers. The island's trees seem to be alive in 1803, but, as we'll see, they don't last long.

Plot Seeds for 1803

-Trindade's natural hazards probably ended initial Portuguese settlement attempts in the early 19th century, but the abandoned houses, paths, and fields provide an eerie setting. In a fictional alternative version, it looks like the settlers died of starvation and were stripped to the bone by land crabs where they fell... but who carried off the skulls, and why? And why do the storms on the island have lightning without thunder? You didn't notice it at first, between the waves and the rain...

5. The Explorer: James Clark Ross, 1839

 The Ross Antarctic Expedition briefly stopped on Trindade on its way south.

As a magnetic station, our observations here were utterly valueless, but the results may be useful by pointing out, in a striking manner, the great amount of error to which those made on shore are liable. Three dipping needles placed at only just sufficient distance apart to ensure their not influencing each other, indicated as much as three degrees difference of the dip, and all of them considerably less than that corresponding to the geographical position. To as large an amount also were the observations of variation vitiated by the local disturbing magnetic influence, whilst those taken on board our ships were perfectly free from these errors.

Horsburgh mentions that the island abounds with wild pigs and goats; one of the latter was seen. With the view to add somewhat to the stock of useful creatures, a cock and two hens were put on shore; they seemed greatly to enjoy the change and, I have no doubt, in so unfrequented a situation, and so delightful a climate, will quickly increase in numbers. 

-Voyage to the Southern Seas, James Clark Ross.

Plot Seeds for 1839

-The minor magnetic deviation reported by Ross is entirely normal and explicable. Your players don't necessarily know that. Quoted out of context, this could be an interesting fact (or a red herring) for any expeditions to the island to discover with a Library Use roll.
 
-You and your fellow PCs are chickens, released into a strange and hostile world.

6. The Pirate: The CSS Georgia, 1863

As I said in the introduction, Trindade is fractally interesting. I discovered this visit while researching section 9.

A highly interesting communication about Trinidad has been received at the Bureau of American Republics from Mr. J. M. Morgan, who, during the late war, was a lieutenant in the Confederate Navy, and during the former Cleveland administration was United States Consul-general at Melbourne, Australia. Mr. Morgan, who had been written to on the subject of the ownership of Trinidad by Mr. H. H. Marmaduke of the Bureau of American Republics, says in answering:

"In reply to your inquiry concerning the Island of Trinidad, the title of which is now in dispute by Great Britain and Brazil, I would state that it does not belong to either of them. Strange as it may appear, the title legally rests with the United States, as the residuary legatee of the late Southern Confederacy. 

In the summer of 1863, was a midshipman on board of the S.C. cruiser Georgia, then lying in the harbor of Bahia, Brazil, in company with the Alabama. Capt. Semmes decided to cruise o the southward of Rio Janeiro, and thence to the cape of Good Hope while the Georgia was to follow as far south as Rio and then proceed to the island of Trinidad for coal, our collier having been ordered there, and also for the purpose of making a digression in favor of the Alabama. 

The Island of Trinidad is a very picturesque spot. It is six miles in circumference and 800 feet high. Alongside of it, at the eastern end, and helping to form the little harbor, is the ‘Monument,' which is some 250 feet in diameter and rises out of the sea to a height of 1,200 feet. Here the Georgia lay for some six weeks. Vessels, after rounding the Cape of Good Hope, or Cape Horn, endeavor to sight Trinidad for the purpose of seeing if their chronometers are all right, and then mark their courses for New York or Liverpool , and while we lay in this cove, or harbour, we ‘brought to’ many merchant vessels. The first intimation they would have that a Confederate cruiser was in the neighborhood would be a shot skipping across their bows. Here it was that we captured and burned in the harbor the ship Constitution of Boston, and also captured and bonded the City of Bath, of Bath, Me. 

Trinidad is an ideal coaling station for commerce destroyers or a naval station for the protection of commerce. It is habitable, although not inhabited. When the Georgia took possession, a few wild hogs and millions of sea fowl were the only living things to be seen. 

Trinidad could be easier defended than Gibraltar, and is naturally a stronger position. In certain winds the waves, with the full sweep of the Atlantic, strike the island and send the spray some 300 or 400 feet into the air. The sight beggars description. At the time the Georgia took possession and made it a Confederate coaling station the island of Trinidad was not claimed by any nation. Had it been so, Capt. Maury was much too careful a commander to have broken the neutrality laws by taking prizes in there, coaling ship without permission, and ‘heaving to’ neutral ships as he lay at anchor in the harbor."

-The Pilot, Aug 17th, 1895

Plot Seeds for 1863

-The film Sahara (2005) is by no means good, but the core idea - a secret Confederate gold shipment in a preposterous location - could easily work on Trindade.

-Trindade could also work as a bastion of the Confederate cause long after the war ends. A few crazed die-hards and a wrecked ship could interfere with treasure-hunting schemes.

Flavio Forner, National Geographic

7. The Treasure-Hunter: E.F. Knight, 1881

Edward Frederick Knight had an extraordinary life. In 1880, he sailed up and down South America in a 30-ton 42'-long yacht. His book, The Cruise of the 'Falcon', contains the most poetic and unsettling description of Trindade.

This is the text to give your Call of Cthulhu or Delta Green group. The book went through several printings in the late 19th and early 20th centuries, so finding a suitably foxed copy to hand to your players is trivial.

When my men heard of my intention of sailing to this lone island of the South Atlantic, they expressed great delight, especially when they learnt that pigs and goats were reported to be its sole inhabitants. On this, the 23rd of November [1881], being our ninth day out, Trinidad was about 1000 miles to the north-east of us.

[...]

This savage spot afforded a good specimen of the nature of the island. Utterly barren mountains rose from a coral beach, mountains that were rotten — and the whole island is so — burnt and shaken to pieces by the fires and earthquakes of volcanic action.

What struck us as remarkable was, that though in this cove there was no live vegetation of any kind, there were traces of an abundant extinct vegetation. The mountain slopes were thickly covered with dead wood, wood, too, that had evidently long since been dead; some of these leafless trunks were prostrate, some still stood up as they had grown; many had evidently been trees of considerable size, bigger round than a man's body. They were rotten, brittle, and dry, and made glorious fuel. This wood was close grained, of a red colour, and much twisted. When we afterwards discovered that over the whole of this extensive island, from the beach up to the summit of the highest mountain — at the bottom and on the slopes of every now barren ravine, on whose loose rolling stones no vegetation could possibly take root — these dead trees were strewed as closely as is possible for trees to grow ; and when we further perceived that they all seemed to have died at one and the same time, as if plague-struck, and that no one single live specimen young or old was to be found anywhere, — our amazement was increased.

At one time Trinidad must have been one magnificent forest, presenting to passing vessels a far different appearance to that it now does with its inhospitable and barren crags. The descriptions given in the Directory allude to these forests; therefore, whatever catastrophe it may have been that killed off all the vegetation of the island, it must have occurred within the memory of man.

I don't mind telling you that, while researching this article chronologically, this text gave me a proper chill. Land-crabs and seabirds are adorable when seen with modern eyes, but something about a dead forest, with every tree withered at the same time, on a deserted island of volcanic stone, filled me with genuine creeping dread.

We slowly toiled up the ravine, and wearisome work it was; sometimes on one side, sometimes on the other, of the watercourse, at times floundering through it, according as one or the other offered the safest and easiest route. The ascent was steeper than we had anticipated, and great rocks fallen from above offered constant obstructions. The dead trunks of trees everywhere crossed the stream. Of vegetation there was at first none but a wiry long grass which covered the soil, wherever there was any. But after we had ascended a considerable distance we came across those beautiful products of the tropics, the tree-ferns.

At first, of small growth, they filled up the hollow of the stream only, having exactly the appearance of our common English fern, but higher up we found them extending their fan-like masses of vivid-green leaves from the summits of lofty trunks.

At last we reached the summit of the ravine and were on the Col, for such it was, a gentle depression between two mountains, and here found ourselves in the midst of a very different nature, and enjoyed the loveliness of a scene such as we little guessed stern Trinidad concealed within its encircling wall of wild crags. For now we saw no rocks, we were walking on a soil powdery and soft and dry, into which our feet sank. The mountain that rose above us on our left was a gentle dome of similar soil ; and all. was covered with a rich and beautiful vegetation. We were walking through a dense grove of tree-ferns, whose branches meeting overhead, like cathedral aisles, allowed but a subdued light to fall on the soft floor below, where millions of land-crabs crawled about ; for these hideous beasts, swarm on this island even to the mountain-tops. Other life there was none, not even insect.

A gentle breeze blew over the Col from the windward side of the island, very grateful to us after our ascent of the hot, windless ravine. The scene, with its fresh green, seemed very beautiful to us at the time, as beautiful as anything we had ever seen. But after a month on the barren sea, and after the contrast of the dreary coast-scenery beneath us, any vegetation could not but seem very beautiful.

On the summit of the mountain there appeared to be some other tree growing with a darker foliage, but we left the inspection of this for our return journey, for we wished without delay to descend to the windward side of the island, which seemed to hold out a magic attraction for us. 

[...]

Certainly the whole nature, live or dead, of this lonely island has something uncanny about it that dismays and appalls the imagination. This ravine, with its black rocks, varied occasionally by red volcanic debris, its strange vegetation of dead trees throwing out their skeleton arms, and its inhabitants savage, foul birds, and the still more offensive-looking land-crabs, struck us as having a particularly ghastly and spirit-depressing appearance. Among such scenery one felt as if anything horrible might happen at any moment, and a vague feeling of insecurity seized the mind.

[...]

We wandered on, opening out bay after bay for some hours, till on traversing a rocky promontory we came to an extensive gulf, backed on its further side by the huge mass of Sugar-loaf mountain; great walls of rock surrounded it, and altogether it was as inhospitable-looking a place as shipwrecked sailor was ever cast on. Now all the shore of this gulf was strewed with wreckage. Along the whole of this windward coast we had perceived many spars, barrels, timbers, and other remains of vessels, but here they were in much larger quantity than elsewhere, so we named this dreary spot Wreck Bay. From its position in the region of the south-east trade-winds a vast amount of drift and many derelict vessels must of a necessity be driven on to the windward coast of Trinidad, and indeed there was a marvellous accumulation. Judging from its appearance some of - this timber must have lain here for hundreds of years, and doubtlessly this beach preserves naval remains of every age since first vessels doubled the Cape of Good Hope. Apart from masts, barrels, and other driftage, we observed that more than one vessel, derelict doubtlessly, had been driven bodily on to the island, for we frequently saw two circular rows of ribs rising from the sand, with the corroded bolts sticking in them here and there, showing where the frame of some fine old ship lay buried.

What struck me as remarkable was that some of this wreckage had been cast up a great distance above what I judged to be high-water mark. Far up, jammed between two rocks, I perceived a huge iron beam that must have weighed many tons.

Again, this island is tailor-made for RPG adventures. 

For some reason or other all hands were more or less ill on leaving Trinidad ; I was myself suffering from symptoms of malaria, which had been troubling me for some time, and which the recent fatigues I had gone through had much aggravated, so that I was debilitated and worn with fever, and almost unfit to work at all. The crew were no better. What was the matter with them, I could not pretend to say, for they had visited no malarious regions. I suspect that some of the fish we had caught and eaten were unwholesome, and we certainly had been indulging for some days on an exclusively fish diet.

Plot Seeds for 1881

-You've been shipwrecked on this horrible rock in the middle of the South Atlantic. There's just enough timber to build a raft and try to sail the 700 miles to Brazil. It's an old plot, but it checks out.

-There's a disease on Trindade. The crew of the Falcon were lucky to make it out alive... and unchanged.

-This is not a place of honour. How obvious do the Atlantean physical markers need to be to stop people from digging up their nuclear waste?



Artist's rendering of Shackletons's apocryphal ad.

8. The Treasure-Hunter Returns: E.F. Knight, 1889

Eight years later, Knight decided to return to Trindade. He'd heard a rumour of buried treasure, considered it plausible, recruited a crew, and set off to search for it. Six months of treasure-hunting, on an island implacably hostile to human life. The Cruise of the 'Alerte' is a genuine adventure.

This journey is less interesting, for our purposes, than his first impressions, but the whole text is worth a read. Knight and his crew took constant casual risks. Life was simpler then, and, if you trusted people a whisker less competent than E.F. Knight, shorter too.

'Captain P—— took a liking to him, and showed him kindness on various occasions. This man was attacked by dysentery on the voyage from China to Bombay, and by the time the vessel reached Bombay he was so ill, in spite of the captain's nursing, that he had to be taken to the hospital. He gradually sank, and when he found that he was dying, he told Captain P——, who frequently visited him at the hospital, that he felt very grateful for the kind treatment he had received at his captain's hands, and that he would prove his gratitude by revealing a secret to him that might make him one of the richest men in England. Captain P—— says that he appeared very uneasy about this secret, and insisted on the door of the ward being closed, so that there might be no listeners. He then asked Captain P—— to go to his chest and take out from it a parcel. The parcel contained a piece of old tarpaulin with a plan of the island of Trinidad on it.

'The man gave him this plan, and told him that at the place indicated on it—that is, under the mountain known as the Sugarloaf—there was an immense treasure buried, consisting principally of gold and silver plate and ornaments, the plunder of Peruvian churches which certain pirates had concealed there in the year 1821. Much of this plate, he said, came from the cathedral of Lima, having been carried away from there during the war of independence when the Spaniards were escaping the country, and that among other riches there were several massive golden candlesticks.

The story is, as Knight points out, a stereotypical example, but he apparently believed enough to return to Trindade.

As the stores would put down the vessel a good deal, we took out of her a corresponding weight of ballast—about eight tons. Two tiers of lead were removed from under the saloon floor, and in the space thus gained we stowed the greater part of our tools. Among these was a complete set of boring apparatus constructed for us by Messrs. Tilley, by means of which we should be enabled to explore through earth and rock to the depth of fifty feet. We also carried a Tangye's hydraulic jack, capable of lifting twelve tons, which we found of service when large rocks had to be removed from the trenches. Shovels, picks, crowbars, iron wheel-barrows, carpenters' and other tools; a portable forge and anvil, dogs and other materials for timbering a shaft if necessary, and a variety of other useful implements were on board. We took with us two of Messrs. Piggot's large emigrant tents, wire-fencing with which to surround our camp and so keep off the land-crabs, a few gardener's tools and seeds of quick-growing vegetables for the kitchen-garden which we intended to plant on the island—a horticultural scheme which never came off in consequence of the want of water—taxidermic gear with view to the rare sea-birds that breed on the island, medical stores and surgical instruments, fishing-tackle; and, in short, we were well-equipped with all needful things, a full inventory of which would nearly fill this book.

Neither did we omit the precaution of arming ourselves in case any one should choose to molest us, a not altogether improbable event; for there was a talk of rival expeditions starting for the island at the very time we were fitting out; our plans had been fully discussed in the newspapers, despite our attempt to keep secret our destination at least; and I called to mind the Yankee vessel that had endeavoured to anticipate the 'Aurea.' Should some such vessel appear on the scene just as we had come across the treasure, it would be well for us to be prepared to defend it.

Each man, therefore, was provided with a Colt's repeating-rifle, and in addition to these there were other rifles and several revolvers on board, and no lack of ammunition for every weapon. The Duke ofSutherland kindly lent us one of Bland's double-barrelled whaling-guns, which was carried on his Grace's yacht, the 'Sans Peur,' during her foreign cruises. This was a quick firing and formidable weapon, discharging steel shot, grape, shell, and harpoons, and capable of sending to the bottom any wooden vessel. I think the sight of it inspired some of my crew with ideas almost piratical. I have heard them express the opinion that it was a shame to have such a gun lying idle on board, and that an opportunity ought to be found of testing its powers. 

The proper adventuring mindset: an extensive inventory and ludicrous firepower.

We knew that the Portuguese had laid claim to Trinidad something like two hundred years ago, and it was possible that the Brazilians, as successors to the Portuguese in this quarter of the globe, might consider the island as their own, and assert their right to any valuables we might find upon it. I need scarcely say that I had made up my mind, should we find the treasure, to sail directly to some British port. I would not trust myself in any country of the Spanish or Portuguese; for once in their clutches we should in all probability lose all the results of our labour. The Roman Catholic Church of Spain or Lima might, with a fair show of right, demand the treasure as her own; so might the Governments of Peru, Chile, Brazil, Spain, or Portugal. But if we could once secure it, get it safely home, and divide it, it would be exceedingly difficult for any one to establish a better right to it than we could—for should we not have the right of possession, with nine-tenths of the law on our side?  

Don't count your chickens before they're hatched, but be prepared to start a war to defend them. 

It would, of course, have been very pleasant for me to have selected my volunteers from among my own friends, especially those who had been at sea with me before; but this I found to be impossible, at any rate at such short notice. I knew dozens of men who would have liked nothing better than to have joined me, but all were engaged in some profession or other which it would have been folly to have neglected for so problematic a gain. The type of man who is willing to toil hard, endure discomfort and peril, and abandon every luxury for nine months on the remote chance of discovering treasure, and is, moreover, willing to pay 100l. for the privileges of doing so, is not to be found easily, either in the professional or wealthy classes.

There are, doubtless, thousands of Englishmen willing to embark on a venture of this description, but it is obvious that there is a likelihood of a fair percentage of these volunteers being adventurers in the unfavourable sense of the term—men anxious to get away from England for reasons not creditable to themselves, men, too, of the rolling-stone description and more or less worthless in a variety of ways, and who would be more likely than the paid sailors to wax discontented and foment mutiny. I realised that the selection of my men should be made with great care.

Of volunteers I had no lack. An article in the St. James's Gazette describing my project brought me applications to join from something like 150 men.

Some of the letters I received were great curiosities in their way, and would cause much amusement could I publish them. I interviewed some sixty of the applicants, and this was certainly far the most arduous and difficult work connected with the undertaking, so far as I was concerned. I shall never forget how weary I became of the repetition to each fresh visitor of the conditions and object of the voyage, and with what dread I looked forward to my visits to the little club at which these interviews were held.

It's straight out of Treasure Island or some other adventure story. A proper rogue's gallery of the inexperienced, enthusiastic, and treasure-mad.

As we neared [Trindade], the features of this extraordinary place could gradually be distinguished. The north side, that which faced us, is the most barren and desolate portion of the island, and appears to be utterly inaccessible. Here the mountains rise sheer from the boiling surf—fantastically shaped of volcanic rock; cloven by frightful ravines; lowering in perpendicular precipices; in places over-hanging threateningly, and, where the mountains have been shaken to pieces by the fires and earthquakes of volcanic action, huge landslips slope steeply into the yawning ravines—landslips of black and red volcanic débris, and loose rocks large as houses, ready on the slightest disturbance to roll down, crashing, into the abysses below. On the summit of the island there floats almost constantly, even on the clearest day, a wreath of dense vapour, never still, but rolling and twisting into strange shapes as the wind eddies among the crags. And above this cloud-wreath rise mighty pinnacles of coal-black rock, like the spires of some gigantic Gothic cathedral piercing the blue southern sky.

[...]

My companions had expected, from what I had told them, to find this islet a strange, uncanny place, barren, torn by volcanic action and generally forbidding, and now they gazed at the shore with amazement, and confessed that my description of its scenery was anything but exaggerated. It would be impossible to convey in words a just idea of the mystery of Trinidad. The very colouring seems unearthly—in places dismal black, and in others the fire-consumed crags are of strange metallic hues, vermilion red and copper yellow. When one lands on its shores this uncanny impression is enhanced. It bears all the appearance of being an accursed spot, whereupon no creatures can live, save the hideous land-crabs and foul and cruel sea-birds.

This description is similar to Knight's first visit, but it's worth repeating. Trindade is a strange, unearthly place.

While we were discussing things, there suddenly came a violent thumping on the deck above us, and from the shouts and laughter of the men we knew that something exciting was going on; so we went up the companion-ladder to see what the fun might be. We found that a fair-sized shark was tumbling about the deck in very active fashion, while Ted was dodging him, knife in hand, ready to give him his coup de grâce. Our sportsman had got his lines out as soon as all had been made snug on deck, but his sport for the first hour consisted of nothing but sharks, of which he caught several. After this he had better luck and was able to supply the cook with fish enough for dinner and breakfast for all hands.

The sea round Trinidad swarms with fish; but, for some reason, though we got as many as we required, they were not to be so readily caught now as at the time of my first visit; for then we hauled them in as fast as we could drop our hooks in the water.

There are various species of edible fish here—among others, dolphins, rock-cod, hind-fish, black-fish, and pig-fish. None of these hot-water-fish are to be compared in flavour to those of Europe, and we found that the sharks were the least insipid of the lot; stewed shark and onions is not a dish to be despised.

Plot Seeds for 1889

-Journalist and gentleman-adventurer Edward Frederick Knight has put an ad in the papers, recruiting crew for a treasure-hunting expedition. Are you willing to put up £100 (around £16,000 in 2025) for a share of a treasure worth millions? Are you willing to sail to the ends of the earth, dig in arid conditions, endure awful food, thirst, land-crabs, foreigners, and fevers? No experience with sailing or exploration is required. 

-It's a race. Knight was right to worry about a rival crew turning up, but luckily, your crew has a different idea of where to dig. When your works are sabotaged, it's only natural to blame the only other humans for hundreds of miles. Will you take revenge? Who'd believe a third faction at work? Land-crabs aren't organized. They can't crush a man's head with a falling boulder or cut the pipes of a salt-water distillery.

 -Some slow poison seems to be affecting the island. Is it merely human interaction? Was the abundance of fish on the first visit due to nutrient-rich runoff from the dying forest, or did overfishing, coral-reef anchoring cause the decline? It can't be merely seasonal variation; the dates overlap. What strange metal or curious relic was buried with the pirate's hoard? 

Just look at those contour lines.

9. The Prince: James Harden-Hickey, 1893 

After the Portuguese, British, Brazilian, and assorted other claimants had come and gone, in 1893, minor celebrity James Harden-Hickey claimed Trindade for... himself, creating the Principality of Trinidad

BARON HARDEN-HICKEY, who claims proprietorship of the island of Trinidad, is a travelled French gentleman, of Irish extraction, who married a daughter of Mr. H M. Flagler, the Standard Oil magnate. The baron thought, as no one else seemed to care for the island, be would take it, organize an absolute monarchy, and send a colony down there.
-The Pilot, Aug 17th, 1895

On Sunday, Nov. 5, 1893, the New York Tribune gave him front-page publicity with an exclusive story on his scheme to transform Trinidad into an independent country. Harden-Hickey argued that "…the inland plateaus are rich with luxuriant vegetation… The surrounding seas swarm with fish… Dolphins, rock-cod, pigfish, and blackfish may be caught as quickly as they can be hauled out…the exportation of guano alone should make my little country prosperous…"

Harden-Hickey’s announcement did not precipitate a world crisis. In January 1894 [sic], when he proclaimed himself James I, Prince of Trinidad, some nations even recognized him. One reporter interviewed his father-in-law, who seemed surprisingly tolerant of the adventure. He said, "My son-in-law is a very determined man… Had he consulted me about this, I would have been glad to have aided him with money or advice... But my son-in-law means to carry on this Trinidad scheme, and he will."

The Prince announced that Trinidad would be a military dictatorship. Its flag would be a yellow triangle on a red ground. He began selling bonds for 1000 francs or $200, announcing that anyone purchasing 10 of them was entitled to a free passage to the island. In San Francisco, Harden-Hickey purchased a schooner to transport colonists and ferry supplies and mail between Trinidad and Brazil. He hired an agent to negotiate the construction of docks, wharves and houses. He also contracted for Chinese coolies to provide an instant proletariat. On Dec. 8, 1893, he instituted the Order of Trinidad, an order of chivalry in four classes to reward distinction in literature, the arts and the sciences. He then commissioned a firm of jewelers to make a golden crown and issued a set of multicolored postage stamps.

-William Bryk, NY Press (for a more complete article, see here)

The ship and labourers never left the harbour. The scheme slowly imploded, along with Harden-Hickey's mental health.

Plot Seeds for 1893

-While Harden-Hickey's scheme is laughable in practice, it has a glimmer of potential legality. Possession is nine tenths of the law though. Every prince needs an evil vizier. All you need to do is keep his most serene highness on track, pay a few bills, and you can literally live like kings.

-There are relatively few fresh sources of the blood and bodies of kings. Harden-Hickey's touch cures scrofula, but he doesn't know it. Plenty of ancient sacrificial rituals (or cultists who've read Frazer's Golden Bough and invented new ones) require a royal personage. The rituals just have to occur on the king's own land.

Wikipedia

10. The Doomed: The Worst Journey in the World, 1910

The 1910 Scott Antarctic Expedition is fascinating. Among other things, its members were heroes in search of a righteous cause. If the sordid reality of the Empire, the greed and stupidity and pettiness of the real world, couldn't measure up to their ideals, what cause could absorb their energy and talents? And so these monks of Kipling challenged uncaring and uncomplicated nature. They muddled, suffered, and died. 

But before they reached the Antarctic, they had a few hair-raising adventures along the way.

This island is difficult of access, owing to its steep rocky coast and the big Atlantic swell which seldom ceases. It has therefore been little visited, and as it is infested with land crabs the stay of the few parties which have been there has been short. But scientifically it is of interest, not only for the number of new species which may be obtained there, but also for the extraordinary attitude of wild sea birds towards human beings whom they have never learnt to fear. Before we left England it had been decided to attempt a landing and spend a day there if we should pass sufficiently near to it.

[...]

The tree ferns were numerous, but stunted. The gannets were sleeping on the tops of the bushes, and some of the crabs had climbed up the bushes and were sunning themselves on the top. These crabs were round us in thousands—I counted seven watching me out of one crack between two rocks.

We sat down under the lee of the summit, and thought it would not be bad to be thrown away on a desert island, little thinking how near we were to being stranded, for a time at any rate.

The crabs gathered round us in a circle, with their eyes turning towards us—as if they were waiting for us to die to come and eat us. One big fellow left his place in the circle and waddled up to my feet and examined my boots. First with one claw and then with the other he took a taste of my boot. He went away obviously disgusted: one could almost see him shake his head.

We collected, as well as our birds and eggs, some spiders, very large grasshoppers, wood-lice, cockchafers, with big and small centipedes. In fact, the place teemed with insect life. I should add that their names are given rather from the general appearance of the animals than from their true scientific classes.

It's interesting that in Knight notes, "Other life there was none, not even insect." Knight was not, of course, a trained naturalist, but it's still peculiar that one crew should report abundant insect life while another crew reports none.

The following is Bowers' letter:

"Sunday, 31st July.

 White terns abounded on the island. They were ghost-like and so tame that they would sit on one's hat. They laid their eggs on pinnacles of rock without a vestige of nest, and singly. They looked just like stones. I suppose this was a protection from the land-crabs, about which you will have heard. The land-crabs of Trinidad are a byword and they certainly deserve the name, as they abound from sea-level to the top of the island. The higher up the bigger they were. 

The surface of the hills and valleys was covered with loose boulders, and the whole island being of volcanic origin, coarse grass is everywhere, and at about 1500 feet is an area of tree ferns and subtropical vegetation, extending up to nearly the highest parts. The withered trees of a former forest are everywhere and their existence unexplained, though Lillie had many ingenious theories. 

[...]

The land-crabs are little short of a nightmare. They peep out at you from every nook and boulder. Their dead staring eyes follow your every step as if to say, 'If only you will drop down we will do the rest.' To lie down and sleep on any part of the island would be suicidal. Of course, Knight had a specially cleared place with all sorts of precautions, otherwise he would never have survived these beasts, which even tried to nibble your boots as you stood—staring hard at you the whole time. One feature that would soon send a lonely man off his chump is that no matter how many are in sight they are all looking at you, and they follow step by step with a sickly deliberation. They are all yellow and pink, and next to spiders seem the most loathsome creatures on God's earth."

The Worst Journey in the World has some extremely lively description of the difficulties landing and escaping from the island. It's well worth a read.

reddit

11. The Duel: HMS Carmania and SMS Cap Trafalgar, 1914

In September, 1914, the refitted liner HMS Carmania met the refitted liner SMS Cap Trafalgar, which was disguised as the HMS Carmania, off Trindade. Wikipedia's summary of this battle is pretty good. The two ships fought a spirited, if slightly archaic, battle of broadsides and manually loaded guns. 

I can't find much information about the alleged German naval base on Trindade. Given the conditions and lack of tangible remains, it can't have been too impressive. Landing supplies wasn't any easier in 1914 than in 1910 (or 1700). The shoals allow for anchoring, but I can't imagine a multi-ton coal depot on the shore would be viable. By 1914, if an established colonial power didn't have a permanent naval base on an island, there must have been a pretty good reason.

Plot Seeds for 1914

-In July of 1914, you and your crew performed a daring series of robberies aboard the Cap Trafalgar. To escape the ship's detectives, you stashed the loot aboard, hoping to retrieve it on a later voyage. Unfortunately, war was declared in August, and the Cap Trafalgar is being sent to some remote island in the Atlantic to be refitted as a commerce raider. Can you sneak or inveigle your way aboard, retrieve your loot, and escape? Will a British warship ruin your plans?

-The sea drops precipitously off Trindade. It is a volcanic seamount, after all. The Cap Trafalgar wreck site has not been located, as far as I know. It's probably 5km down. The Titanic is 3.8km down, so locating and visiting this wreck seems unlikely. Who knows what creatures of the deep were stirred up by the descending hulk.

-What if the Cap Trafalgar didn't sink, and managed to sail to Martim Vaz island? What if the Carmania was likewise wrecked on the cliffs of Trindade? You could have duelling island wrecks, each trying to blast the other off the rocks with salvaged guns and jury-rigged boats. Admittedly, this is unlikely, as wireless signals meant other ships were already en route, but war is a chaotic time. One storm, one emergency report, and the islands could be forgotten for years. 

-If both ships went down, the survivors could wash up on the same island, leading to all sorts of adventures while waiting for rescue. Things would probably be civil... at first.

openseamap.org

12. The Prison, 1924

I'm relying on machine translations here, but a brief summary is plenty for RPG purposes. Trindade was used as a particularly cruel open-air prison from 1924 to 1927

Plot Seeds for 1924

-The commandant has read a very interesting English book by a man named Knight. There is buried treasure on this island. Dig or perish.

-One of your fellow prisoners has read a very interesting English book by a man named Knight, and, as proof, has a gold coin. This could be a lie to inspire a revolt. It could be a coincidence. Or it could be that, just over the hill, there's an unbelievable fortune. Enough to finance a hundred revolutions, or retire to some other country under a new name.

Wikipedia

13. The UFO, 1958

Once again, I'm relying on machine translations, but the gist is fairly simple. In 1958, a photographer named Almiro Baraúna allegedly spotted and photographed a UFO. It was, as you may have guessed, a hoax

Plot Seeds for 1958

-Trindade is an isolated alien outpost. Dig for treasure and you might find a hatch.

-Aliens are using Trindade as a test case of human interaction with the environment. It's not looking good.

-If you're going to build a secret alien technology test facility, Trindade is probably a good place to do it, assuming you can ferry things on and off by helicopter. The sun-bleached corrugated metal shacks visible on satellite photos are obviously decoys.

-The hogs left behind by Edmund  Halley in 1700 developed intelligence, an underground civilization, and antigravity technology. The eerie land-crabs are a red herring. 

-There is a portal on Trindade that opens to other times, but not other places. Edmund Halley opened it in 1700, while chasing a falling star. It closed it in 1956, as the star rose again. But in the years between, it might be possible to slip through time.

Fernando Faciole, Discover Wildlife

14. Miscellaneous Facts

Given the British habit of nicking unattended landmasses, articles that touch on Brazilian sovereignty have a tone somewhere between peevishness and pride. It's only to be expected.

Hayunite, or hauyne, is only found in a few places on earth. Trindade is one of them. It's a beautiful mineral, but in the real world, that's about all. In a fictional setting, where cold fusion works or something, it could be extremely relevant. Maybe it's only found on alien landing sites, or it's required for time travel.  

While the island's feral cats were exterminated in 1998, the last goats were apparently eliminated by snipers (!) in 2005. It's possible that these were the descendants of Halley's goats from 1700, but it's probable that other colonists augmented or reintroduced them. Given enough time (or some supernatural help), they could have evolved to resemble Myotragus.

This article mentions a shipwrecked yacht in 1994 and an undated modern fishing vessel mutiny. I can't find sources on either, but it just goes to show that Trindade is still generating plots.

There's a species of beetle, Liagonum beckeri, that lives on one rock in one ravine on Trindade and nowhere else. "The population is restricted to a wet rock of <1m2, inside a deep ravine. [...] The beetles run around only on those parts of the rock that are covered with a green algal biofilm." It'd be extravagant to use the whole rock.