OSR: Arms and Armour: The Power of Plate

OSR-type-games traditionally use one number to represent how hard a character is to hit. For the purposes of this article, we're going to call that number Armour Class (AC).Dexterity (the stat) might increase* that AC. Wearing armour also increases AC*. The higher** the number, the less like a character is to take damage.

*Or decreases, if you're using descending armour class, but you get the idea.
**Or lower, see above.

And that's usually fine. It's just a game after all. It's not a game about armour or even (arguably) a game about fighting.

But it's also not very realistic. Armour doesn't work like that.

Desperta Ferro no 4

How Does Armour Work

I'm going to lean on this article by Bret Devereaux fairly heavily. It (and the entire blog) explains complex topics in a clear, pop-culture-accessible way. You can also look up hundreds of videos of reenactors and enthusiasts doing surprising things in armour.

Armour is good. Humans are squishy. Everyone who could afford to wear armour did. "Afford", in this case, means both financially and energetically. Armour is heavy; if you can't do your job while wearing it, you'll die anyway.
 

Why Realism?

Because the real world, particularly the past, is interesting, weird, and unintuitive. If you can make realistic things work in your games, they can add a layer of complexity and value.

If you can't, they can add a layer of tedious and pointless bookkeeping. There are a lot of systems out there that claim to "fix D&D" by emulating "realistic medieval combat". Nine times out of ten, they're enthusiastic and detailed but utterly tedious. Stances and guards and fifty different kinds of polearms. Rules for every helmet. There's a market for that kind of complexity, but I like simple rules to explain complex concepts.
  

Trade-Offs

Cost and Abundance: tend to only matter in the first few sessions. Once the PCs have money, they'll try to buy the best gear locally available.

Inventory Slots: a better trade. The more Inventory Slots you fill with Armour, the fewer you have for weapons, tools, and supplies. (Inventory Slots are equal to a PC's Strength score, or 10, or 12, or some other arbitrary but low number.)

Stat Penalties: a strange trade. The better your armour, the fewer roles you can perform. You are less likely to set up an ambush and more likely to be caught while running away.

Assumptions

It's the 14th century... ish, Europe... ish. Full plate armour exists, but is not particularly common. Firearms and cannons are primitive. Everything exists in a murky transition between feudal power and monarchical states. Mercenaries are becoming more common. Wizards are present, but not common and not apocalyptically powerful.
 

Damage Types

For clarity.

Slashing. The most common type. Animals with claws, swords wielded by untrained users, etc. If you can do it with a bread knife, it's Slashing damage. Makes a horrible mess of unarmoured flesh but is defeated by most armour.

Piercing. Pressure applied at a point. Daggers, arrows, crossbow bolts. Arrows are a borderline case in some ways, but I didn't want to give them a separate damage type. Piercing damage punches directly through armour or, more likely, hits a weak point like a joint or a gap.

Bludgeoning. Pressure applied broadly. Hammers, chair legs, trampling. Big bruises, concussions.

Crushing. Unstoppable pressure. A hippo's bite, falling off a cliff, a hammer trap, etc. Turns plate armour into a squashed tin can. Typically, not reduced by armour or spells. Firearms and cannons might deal Crushing damage.
Elemental. Acid, Ice, Fire, Ice, Lightning, Stone (maybe? Might be covered by other damage types), Void (Sonic), and Water. Stuff you can't avoid, even in armour. Hot sand or oil deals fire damage.

Magic. The darkest magic. Or just regular magic. Bypasses mere metal, leather, and flesh. Sometimes deals damage directly to a creature's soul.

Branca branca branca!

Rules

 
Leather Armour
"Leather Armour" is fictional; armour made of leather existed. This tier covers quilted fabric, fish leather, wood, hide, etc. It's cheap. It's abundant. Leather Armour occupies 2 Inventory Slots and reduces incoming Slashing damage by 3. It does not penalize Stealth or Movement.

Chain Armour
Chain armour is expensive. It occupies 4 Inventory Slots and reduces incoming Slashing damage by 6.

Plate Armour
Very expensive. It occupies 6 Inventory Slots and reduces incoming Slashing and Bludgeoning damage by 6, and Piercing damage by 4.

Shields
Common. A Shield occupies 1 Inventory Slot and must be wielded in 1 hand. It reduces incoming Slashing, Bludgeoning, and Piercing damage by 2. A shield can also be sundered, destroying it but reducing incoming damage from one source by 1d12.

Magic Armour
Very rare, possibly temporary, possibly cursed. Reduces incoming Magic damage by some amount. Enchanted shields, amulets, charms or caps are also viable. Magic Armour can also decrease or completely negate Elemental damage.

Bits of Armour
You can subdivide armour into pieces, granting fractional bonuses or using hit locations. That seems like a lot of effort to me. Yes, a steel helmet and breastplate with limited other armour is realistic, but it rarely seems to come up in play. Either a PC can afford a full suit and wants the full benefits, or they can't and don't.

Axel Sauerwald

Weapons

This list is not exhaustive, but should let a GM assign both damage and size to most weapons.

Improvised
Improvised weapons typically occupy either 1/3rd or 1 Inventory Slots. They deal 1d4 damage and can be thrown 10'. A shield can be used as an improvised weapon.

• Broken Bottles: Slashing
• Rocks, Chairs: Bludgeoning
   

Light
Light Weapons occupy 1/3rd of an Inventory Slot. They can be thrown 30'.

• Daggers: Piercing

Medium
Medium weapons occupy 1 Inventory Slot. If wielded in 1 hand, they deal 1d8 damage. If wielded in 2 hands, they deal 1d10 damage.

• Swords: Slashing or Piercing
• Axes: Slashing
• Hammers: Bludgeoning
   

Heavy
Heavy weapons occupy 2 Inventory Slots. They deal 1d12 damage and must be wielded in 2 hands.
Big Swords Slashing or Piercing damage.

• Big Swords: Slashing or Piercing
• Big Axes: Slashing
• Big Hammers: Bludgeoning
   

Reach
Reach weapons occupy 2 Inventory slots. They deal 1d8 damage, but let the wielder fight from the second rank of a formation, where they can't be hit by anything but Reach or Ranged weapons. They must be wielded in 2 hands.

• Spears: Piercing
• Complicated Polearms: Pick a damage type pair. Slashing and Piercing. Slashing and Bludgeoning. Piercing and Bludgeoning. Though I'd suggest making Bludgeoning damage harder to find, or reducing its damage to a d6.
   

Ranged
Ranged weapons occupy 1 Inventory Slot and have a base 30' range. They must be wielded in 2 hands.

• Bows: 1d6 Piercing
• Crossbows: 1d12 Piercing. Takes 1 round to reload.
   

All melee weapons add the wielder's Strength bonus (usually 0, sometimes +1 or -1, occasionally +2 or -2) to their damage.

Magic weapons either add Magic damage to an attack, or turn all the attack's damage into Magic damage (or Elemental damage).

• A +2 Dagger might deal 1d6 Piercing damage and 2 Magic damage, or it might deal 1d6+2 Magic damage. Depends on your system and preference.
• A +2 Dagger of Fire might deal 1d6+2 Fire damage, 1d6 Fire damage and 2 Magic damage, or 1d6 Piercing damage and 2 Fire damage. Again, there are a few ways to divide damage.

 

Additional Rules Clarification

Attack rolls vary with system, class, level, etc, but should be somewhere between 50% and 90%, in ideal conditions. Critical Hits, (a 1-in-20 chance) deal double damage.

Being prone reduces damage reduction by half. Depending on the system, prone targets may also be easier to hit with melee attacks. "Prone" covers conditions where a target is easier to hit. The more you can do to imperil or impede your target, the better your chance to hit.

Osprey #155

Fearful Symmetry

You can start to see how it all fits together.

Wearing Plate armour and carrying a Shield (the best available mundane defense) reduces most incoming damage by at least 6... but at a cost. A PC's damage output is reduced (because they can't wield a 2-handed weapon). 7 of their very limited Inventory Slots are full of stuff that's only useful in combat, 8 if you include a weapon.

Plate without a Shield still fills up 6 slots. Piercing weapons can sneak through a few extra points of damage, but in return, a PC can wield a mighty two-handed weapon and deal some significant pain.

Chain is a decent compromise. Damage reduction against the most common form of damage, especially in a dungeon, but relative vulnerability to both Bludgeoning and Piercing damage. A shield helps cover those gaps.

Leather only occupies 2 Inventory Slots, so it's viable for low-capacity PCs, or PCs who need to carry a lot of other items. It doesn't penalize Steath or Movement, so sneaky-types can wear it without fear.

No armour is also viable. If you don't get hit, you don't need to worry about damage reduction, and there are a lot of ways to not get hit. And you've got all those sweet Inventory Slots to fill with items that can save your life, or get you rich, in non-combat situations.

Inventory switching becomes a critical issue. In the GLOG, the first 3 Inventory Slots are quick-draw, meaning a PC can access them immediately. They could be weapons, vital tools, spellbooks, a lantern, etc. Anything else requires 1 full round to access.

If a PC wants to focus all their resources on combat, they may want to pick Plate armour (in their general inventory), a Shield (in 1 quick-draw slot), a Sword (in 1 quick-draw slot), and... well, something else. With 9 Inventory Slots full of stuff, and with weapon and shield at the ready, they're in trouble if they get into a non-combat situation. Holding a lantern or torch will be difficult; they'll need to drop it to draw their sword and raise their shield.

Wheeeee...
Cavalry charges hurt.

Rock Paper Scissors... Lizard Spock

The discussion so far has focused on equivalent arms and armour: fights where both sides have the same tools and tactics. But typical dungeon inhabitants change the considerations.

Giant Spiders, Centipedes, etc.
Armour as leather (-2 Slashing damage) or unarmoured. You could also add bonus damage from bludgeoning sources. Chitin is fragile. They typically deal Piercing damage (bites), plus secondary effects (poison, paralysis, etc.)

Goblins, Kobolds, etc.
Unarmoured, or Leather (-2 Slashing damage). Some organized goblins might have shields (-2 Slashing, Bludgeoning, and Piercing damage). They typically deal Piercing damage (daggers,  spears, arrows).

Orcs, Hobgoblins, etc.
Leather (-2 Slashing damage) or Chain (-6 Slashing damage). Sometimes Shields (-2 Slashing, Bludgeoning, and Piercing damage). Rarely, Plate (-6 Slashing and Bludgeoning damage, -4 Piercing damage), but typically with two-handed weapons instead of with a shield.

Mimics, Giant Rats, Zombies, etc.
No armour. Typically deal Slashing or Bludgeoning damage.

Skeletons, Golems, etc.
Immune to Slashing and Piercing damage. Typically deal Slashing or Piercing damage.

Oozes
Typically immune to Piercing damage. Frequently have other immunities. Typically deal bludgeoning or acid damage.

Ghosts, Liches, Other Horrible Things, etc.
Immune to everything except Magic damage. May take some types of Elemental damage. Typically deal Magic damage.

The conclusion seems clear. Bring many damage types, switch between them, and try to either deal Elemental or Magic damage. But rarity, risk, cost, and lack of inventory space will by necessity limit these options. There's no optimal solution, but there are a lot of interesting solutions. And that's very appealing.

KILART (choe, heonhwa)

Dungeon Tactics

Dungeons are weird environments. Medieval warfare is not designed for 10' hallways, pit traps, and goblins who can see in the dark.

Arms and armour adapt to the pressures faced by their users. Time lag exists, as it always has (and in some fields, always will), but it's worth examining what pressures medieval armour faces underground.

When history moved slowly, as it did before 1900, rulers were slow in learning realities in the exercise of government, and some, like the Bourbons, never learned at all. It took a very long time before rulers came to realize that armed service would have to be paid for or that they needed to concern themselves with the wants of the lower orders from whom their armies were drawn. We have been living since under Henry Adams’ law of the acceleration of changing times, which obscures for us the time lag that existed for our ancestors between the fact of change and the social and political understanding of what had happened.
-The First Salute: A View of the American Revolution

How the "fact of change" and the "understanding of change" will depend on your setting. Is crypt-robbing an established profession, with guilds and a long history? Arms and armour will reflect this. Is it new or sporadic? Arms and armour will be adapted, sometimes imperfectly, from battlefield use.

Maneuvering
Rolling, dodging, leaping, and climbing are all feasible in full plate.

Heat
Mines are warm, but so is the desert, and people wore full plate in the desert. Not worried.

Water
Evidence exists that it's possible, with effort, to tread water and swim along the surface for a few minutes in plate armour. I've yet to see anyone ascend from the depths in plate armour. Drowning is still a very real possibility if someone falls into water or is carrying other heavy items. Just because it's possible doesn't mean it's sensible.

Visibility and Awareness
Armour is noisy. A good helmet, by necessity, restricts vision and hearing. Both are flaws in a dungeon. Corridors echo. Pit traps and ambushes are obscured. I'd expect to see a lot of helmets with folding fronts or visors, so an armoured warrior could switch from scanning mode to combat mode immediately. Forgoing a helmet entirely is still silly, unless you're storing your brain elsewhere.

Training
Cavalry combat is useless underground. Horses are great on an open field. You can't joust, you can't practice a full-speed charge, and you can't rely on your fellow explorers. They're just in it for the gold, after all.

A wall of spears and pikes is still formidable... if you can get it to hold. A formation 30 across and 3 deep is sturdy. In a confined space, with no room to maneuver, wheel, or retreat in good order, that same formation in miniature is very vulnerable to disruption. One fireball, one panicking hireling, one lucky goblin, and the whole formation goes to hell. It doesn't have the width to fill gaps.

So I suspect most "realistic" dungeon fights would be two small groups encountering each other, sizing each other up, possibly charging to within 10' or so, and then, after some posturing, retreating.

Dungeon combat requires much more tactical finesse than most armies in the 14th century could manage. Groups need to coordinate and execute complex plans. They need to adapt to unprecedented situations.
 
Hirelings and Followers
Morale is crucial. People typically won't fight to the death. If they do, it's usually not for high ideals or promises of gold. It's because they want to protect themselves or the person next to them, or because they fear being shamed or outcast for their behavior. That's it.

A peasant hired to hold a torch will be quaking in their boots at every noise underground. At the first sign of combat, they're gone. Running is almost always a better answer than fighting.

A combat hireling will fight based on their leader's charisma; the personal bond between leader and follower, the expectation of a culture, the pressure of tradition. Better pay will help get your hirelings to combat but won't nessesarily hold them in line. A share, or a half-share, instead of wages binds the hireling to a group; they feel like they're part of a unit, not a disposable accessory. Morale tests and reaction rolls are critical.
 
Spare Shields and Weapons
It's definitely worth giving a shield or two to a hireling, but in a combat situation, retrieving a spare shield might not be viable. Access to a variety of weapons is also good.

Marching Order
For groups of 4 or more, marching order becomes critical. Who's in front? Who's watching for ambushes from behind? Where's the squishy wizard?

The most common plan seems to be to put your best fighters in front, your squishy support people in the middle, and backup fighters behind.

Ranged attacks in cramped quarters are tricky. Firing into melee is very dangerous (thought that might not stop a suitably motivated PC). In larger rooms, the ability to deal damage without putting yourself at risk is valuable.

Pedro Krüger Garcia

Downsides

This system can make some dice rolls meaningless.

Traditional One-Number Armour Class

• It's your turn to act. You roll a dice. It's not a hit. Nothing happens. Boo.
• It's your turn to act. You roll a dice. It's a hit. You roll and deal damage. Yay!

New Damage-Reducing Armour

• It's your turn to act. You roll a dice. It's not a hit. Nothing happens. Boo.
• It's your turn to act. You roll a dice. It's a hit. You roll and deal damage. Yay!
• It's your turn to act. You roll a dice. You hit! Yay! You deal damage. Nothing happens. Boo.

Instead of a binary outcome (failure+no damage;success+damage), you've got 3 outcomes, 2 of which end in disappointment (failure+no damage;success+damage;success+no damage).

You could switch to an auto-hit system like Electric Bastionland. All attacks hit; armour reduces damage. Situational bonuses and penalties increase or decrease damage dice size or add extra dice.

But E.B.'s system doesn't really support leveling progression. You're as good as you're going to get when you start. Leveling (such as it is) improves your HP, but doesn't really change your effectiveness.

Bookkeeping
It require a bit more math. Modifying a standard character sheet to list all available damage reductions should save time. I'm not sure the tradeoff is worth it.

Testing
I'm still fiddling with these numbers, but that's the beauty of the concept. Once you've chosen your variables, you can change the values to suit individual tastes. If you think Leather Armour should provide more protection against Piercing weapons, add it.
 

Advantages

Arise My Minions
It makes mass combat math easier. The GM could roll all the attacks individually, but rounding methods save time.

40 goblins armed with daggers (1d6, piercing) attack a knight in plate armour and with a shield (reducing incoming piercing damage by 6). Goblins have a base 50% chance to hit, so 20 attacks hit. Of those, 1 is expected to be a critical hit, so the GM rolls 1d6x2. The Knight takes that much damage, -6 of course.

If the Knight is knocked prone, the goblins have a 70% chance to hit. 28 attacks hit. 1 is expected to be a critical hit, but all 27 other attacks deal 1d6-3 damage. Ouch.

Don't get knocked prone. Goblins will stick daggers in your eyes.

Rewards Versatility
Having a mix of damage types will almost always be rewarding. There's not one universal answer. Piercing damage is good. but some common dungeon creatures (skeletons and oozes) negate it completely. Ranged weapons are good, but you might not be able to use the. Etc. Again, it encourages interesting choices and compromises.

Alters Expectations
It's easy to tell a story about the past that fits our current notions. Just a big pile of tropes, reinforced by other bits of media that are also made of tropes, until any relation to reality vanishes.

Armour is good. Wear it if you can.