2024/09/11

OSR: High-Level Ilusionist Spell Rewrites

In the previous post, I covered low-level Illusionist spells for the Treausure Overhaul. Higher-level spells present their own design challenges. They need to feel more impact than lower-level spells, but won't be cast anywhere near as often.

Sadly for the Illusionist, many canonical high-level spells are upgraded versions of low-level spells, or effects that could be replicated with lower-level spells. Phantasmal force devours the illusion design space. I've tried to condense or combine spells wherever possible.

Minor creation and major creation were moved to ritual spells, joining rope trick and magic mirror and other spells with longer casting times or complex requirements.

Oriana Menendez

1d12 Level 4 Level 5 Level 6 Level 7
1 Boxed Teleport Confusion, Mass Acid Fog• Astral Spell
2 Confusion Shadow Monster II Eerie Terrain Drama
3 Dispel Exhaustion Maze* Geas* Mirage
4 Dispel Magic Project Image Impersonate Invisibility, Mass
5 Emotion Shadow Magic Phantasmal Feast Permanent Illusion
6 Hypnotic Pattern, Improved Shadow Door Pseudocide Prismatic Spray
7 Invisibility, Improved Phantasmal Force, Perfected Repeat Spell Prismatic Wall
8 Massmorph Hypnotism, Mass Shade Shadow Walk
9 Modify Memory Accelerate Time* Shadow Monster III Sunbeam
10 Phantasmal Killer Visitation True Seeing* Time Stop
11 Shadow Monster I Seeming

12 Solid Fog Insubstantiate

Lena Richards

Level 4

1. Boxed Teleport
Illusionist 4
R: 0 T: self D: 0
This spell can only be cast if the caster is alone inside a confined space smaller than a 10’ cube (e.g. a chest, closet, or coffin). The caster teleports to another well-known and clearly visualized confined space smaller than a 10’ cube within [caster level] miles. If the targeted space is occupied or open, the spell fails.

If the caster is willing to drag around a chest, they can pop back to camp or drop off valuables and return for the cost of two level 4 spell slots. Does the stomach of a purple worm count as a confined space?

2. Confusion
Druid 7, Illusionist 4, Magic-User 4   
R: 120’ T: creatures D: [caster level] rounds
Targeted creatures are befuddled. The number of potential targets varies with a creature’s HD.
•0-2 HD: up to 12 creatures
•3 HD: up to 4 creatures
•4 HD: up to 2 creatures
•5+ HD: 1 creature
Roll for each affected creature at the start of their turn. 1d6: 1. Attacks caster’s group, 2. Moves away from caster’s group, 3-4. No action, 5. Moves away from target’s group, 6. Attacks target’s group. Creatures of 3 HD or more may Save each round to act normally.

One of those spells with a lot of rolling and math, but it's a classic, and it's a very powerful effect if the caster gets a few lucky rolls or targets a leader. It's another spell that synergizes with other illusion spells to confuse even creatures that pass their Save.

3. Dispel Exhaustion
Illusionist 4
R: 10’ T: creature D: [caster level]x30 minutes
Up to 4 creatures gain temporary HP equal to half their maximum HP. Once every 10 minutes, creatures may move at 2x normal speed for 1 round. Creatures feel revitalized, restored, and healthy, but exhaustion returns when the spell ends. 

A fairly powerful buff, but temporary HP is not real HP, and it's not "survive Save or Die effects" either. HP loss is very rarely why PCs die. Buffing tanky summoned creature is a great use for this spell.  

4. Dispel Magic
Cleric 3, Druid 4, Illusionist 4, Magic-User 3   
R: 120’ T: creature, object, or magical effect D: 0
Any spells affecting the target, or any magical effect, ends. Spells of lower-level casters are automatically end. Spells of higher-level casters have a 5% chance per level of difference of not ending. Most magic items are not disenchanted by this spell, though any spells affecting them are dispelled normally. Potions and very minor magic items are disenchanted.

A standard tool. Every caster gets access to it because there's plenty of magic nonsense in D&D.

5. Emotion
Illusionist 4
R: 120’ T: area D: [caster level] rounds
In an area 30’ in diameter, the caster adjusts the emotions of creatures for the duration. Hostile creatures may Save to negate. Options could include:
•Fear. Save with a -2 penalty or flee.
•Hate. +2 to attack rolls, damage, and Morale.
•Despair. Save each round to take any actions.
•Rage. +3 to attack rolls and damage. Fearless, but must attack the nearest enemy.
•Admiration. Reroll reaction rolls and choose the more favourable result.
•Bafflement. Spellcasting and complex intellectual activity is impossible.

Creatures that do not know the caster is present aren't technically hostile. Surprise! It's nameless dread! Another spell that buffs summoned creatures (and hirelings, if you don't mind losing a few).

6. Hypnotic Pattern, Improved
Illusionist 4
R: 30’ T: point D: concentration+1d4 rounds
Swirling colours and shapes fill a 15’ radius around the chosen point. The caster may move the point up to 30’ per round, anywhere within line of sight. Creatures in the area that can see the pattern must Save or be hypnotized. Up to 24 total HD of creatures can be hypnotized. Affected creatures will stand and watch the pattern, or move towards its new location, even if this would put them in danger. The effect ends for a creature if it is harmed. The caster may not move while concentrating.

In the original spell, creatures get a Save to notice being lead into danger (off a cliff, into a pit trap, etc.) but that's three Saves for one effect (Save at the start, Save to notice danger, Save when taking damage), and that seemed excessive. Spells should reward cunning play. If the Illusionist wants to use environmental hazards to get rid of 24 HD of creatures, then they should be encouraged to do so.

7. Invisibility, Improved
Illusionist 4   
R: touch T: creature D: 1 hour
As invisibility, 10’ radius, but the effect does not end for a creature when it takes a hostile action. Instead, the creature becomes visible until the start of their next turn. 

This is a very powerful invisibility effect. It's up there with phantasmal force as an Illusionist go-to spell. Flickering in and out of invisibility for an hour, and possibly bring a few other creatures along, is very useful for getting into and out of trouble.

8. Massmorph
Illusionist 4   
R: 240’ T: area D: 24 hours
Any number of willing people in a 120’ diameter area take on illusory appearances. The effect ends for a target if it takes a hostile action, takes damage, or moves out of range of the caster. The illusion can take the form of:
•Trees. A copse, an orchard, a glade.
•Other humanoid creatures. Unconvincing up close.
•Identical copies of the caster.
The same choice must be made for all targets.

Massmorph is an OD&D wargame-style spell that, oddly, wasn't ported to Chainmail. I've updated it to add other options. I am Spartacus.

9. Modify Memory
Illusionist 4, Magic-User 5   
R: 30’ T: creature D: 0
The caster adjusts one of the target’s memories. The event must have occurred within the last 24 hours and lasted no more than 10 minutes. The caster can erase the memory, alter details, overwrite it with another event, or allow perfect recall. An unwilling creature may Save to negate. Hostile creatures Save with a bonus equal to their HD. The target must be able to hear and understand the caster. 

The grammar in this spell is a little awkward, but it's not an effect that English grammar is designed to handle.

10. Phantasmal Killer
Illusionist 4
R: 60’ T: creature D: concentration, up to 6 rounds
Target creature must Save or perceive an approaching terrifying creature. Only the caster and the target can see it. The Phantasmal Killer attacks as a HD 4 creature. On a hit, the target must Save or die of fright. Because it exists only in the target’s mind, it is intangible, can fly, cannot be targeted, and is immune to all damage. The caster does not need to maintain line of sight to the target or the Phantasmal Killer while concentrating.

You might think this is less powerful than a straight-up save or die effect, but the point of a phantasmal killer is to force the target to inconvenient and unwise things. Casting fireball at a creature that doesn't really exist, for example, or surrendering, or causing mass panic among allies. It's an upgraded spook.

11. Shadow Monster I
Illusionist 4
R: 40’ T: point D: [caster level]+3 rounds
Summon up to [caster level] HD of Shadow Monsters. They resemble real creatures chosen by the caster, but are made of solid shadow. All creatures must be of the same type. They are under the caster’s control, have 1d2 HP per HD instead of 1d8, deal ½ damage,  and cannot cast spells or use supernatural abilities. Sapient creatures may Save to see their true form. Shadow Monsters deal non-lethal damage to creatures that pass the Save. 

Shadow monsters is a complex spell in AD&D that requires some on-the-fly percentile math. I've simplified it considerably. Compared to the Druid and Magic-User's summon monster, it creates a larger number of weaker creatures. The caster does get to choose the type, which can be very useful in factional dungeon warfare, or if the caster knows what their enemies fear. I vaguely remember using illusionary tigers to great effect at some point, but I can't remember why. I've split it into 3 spells, to match the summon monster levels.

12. Solid Fog
Illusionist 4
R: 60’ T: point D: 10 minutes
Creates a 10’ cube of opaque fog per [caster level]. The fog is as thick as cotton wool and heavier than air. Creatures in the fog move at 1/10th normal speed and cannot make melee attacks. Strong wind does not affect the fog.

I like the description "as thick as cotton wool." It should let GMs adjudicate the spell in an intuitive way.

João Bragato

Level 5

1. Accelerate Time*
Illusionist 5   
R: 60’ T: point D: [caster level] hours
Time seems to flow 6x as quickly for creatures and timepieces in a 10’ radius around target point. 10 minutes feels like 1 hour; 4 hours feels like 1 day. This may accelerate rest, fatigue from strenuous activity, natural healing, poisons, diseases, and spell recovery. Creatures do not gain extra actions or move more quickly. Spell durations are not affected. Casting this spell more than once in a week causes the permanent loss of 1 Constitution.

Reversed: Time seems to flow 6x as slowly instead.

Adding "and timepieces" is absolutely unnecessary, but it is thematic. Adding the strenuous activity note makes the spell more interesting. Sure, a 10 minute nap feels like 1 hour, but 10 minutes of chopping firewood feels like 1 hour too, so using this spell constantly, despite its long duration, is probably unwise. I'm torn on the constitution drain penalty. I prefer for spells to be balanced on their own instead of needing a special restriction, but there's no way to give it a sufficiently long duration without risking casters spamming it... or overlapping it.

2. Confusion, Mass
Illusionist 5   
R: 120’ T: area D: [caster level] rounds
In a 30’ diameter area, up to [caster level]x3 HD of creatures are befuddled. Roll for each affected creature at the start of their turn. 1d6: 1. Attacks caster’s group, 2. Moves away from caster’s group, 3-4. No action, 5. Moves away from target’s group, 6. Attacks target’s group. Spellcasters may Save each round to act normally.

A better confusion spell, but that's how the Illusionist rolls.

3. Hypnotism, Mass
Illusionist 5
R: 50’ T: creature D: [caster level]+3 rounds
The caster speaks a short, simple, and reasonable command to [caster level] creatures within range. The creatures must Save or obey. Targets must be able to hear and understand the caster. The command must be a plausible course of action.  

It was a toss-up between including this or a multi-target long-duration suggestion. In the end, a shorter command with more targets felt more sensible. There's less for the GM to track.

4. Insubstantiate
Illusionist 5
R: 60’ T: creature or object D: [caster level] rounds
Target creature of [caster level] HD or below, or target object that fits inside [caster level] 1’ cubes, phases out of reality. It cannot affect the world or be affected by it. It moves at ½ normal speed and can pass through solid obstacles with effort. The target is shimmering and translucent.

A versatile spell. Get rid of doors, prevent someone from grabbing a vital object, temporarily exile a monster, etc. Yes, it has all the problems of wraithform and gaseous form, but it's a high-level spell slot.

5. Maze*
Cleric 6, Illusionist 5, Magic-User 8   
R: 60’ T: creature D: varies
Target creature is transported to an extradimensional maze. The maze is not harmful, but the caster may specify aesthetic touches or implied threats. The target is is trapped for:
•Int. 3-8 (below average): 1d6 hours
•Int. 9-12 (average): 1d6x10 minutes
•Int. 13-18 (above average): 3d6 rounds
When the spell ends, the target reappears in the nearest empty space to their last position.

Reversed: Target creature learns the most direct path to the exit of a building, dungeon, maze, labyrinth, catacomb, cavern, or other mappable structure. The path may reveal secret doors, but will not solve puzzles or reveal traps, provided a valid path exists through them. It will try to avoid locked doors if possible.

While the reversed maze might be a headache for GMs, I think it's useful to give players a plausible way of escaping a dungeon.

6. Phantasmal Force, Perfected
Illusionist 5   
R: 240’ T: point D: 10 minutes / permanent
As phantasmal force, but the illusion is smaller than a 120’ cube, may create noises, odours, mild temperature adjustments, and has realistic texture. Saves to see through the illusion have a -4 penalty. When cast, instead of creating an illusion with a 10 minute duration immediately, the caster may set conditions which will trigger the spell. The conditions can be as complex as desired, but must occur within 30’ of the point, and must rely on external appearances or visible actions.

I mashed together a few similar spells to create this one.

7. Project Image
Illusionist 5, Magic-User 6   
R: 120’ T: point D: [caster level] rounds
A perfect intangible image of the caster appears at the designated point. The image moves, speaks, and acts identically to the caster. The caster may see, hear, and cast spells through the image as if they were present at the image’s location.

The fact that the image duplicates the caster's movements makes this spell tricky to use for schemes, but it's still fairly useful. The free range and scouting is nice.

8. Seeming
Illusionist 5   
R: 30’ T: creature D: [caster level]x2 +2d6 rounds
The target takes on the appearance of another person or creature of approximately the same size. The caster may create a perfect visual copy of a well-known creature or a general type of creature. For every 2 [caster levels] past the first, the caster may target another creature. Illusionary equipment is also provided, but vanishes if dropped. The illusion ends for a creature if it takes damage.

An upgraded disguise spell. I might rename this to "diguise, mass" to make cross-referencing spells quicker.

9. Shadow Door
Illusionist 5
R: touch T: object D: [caster level] rounds
The caster creates an illusory door on a solid surface and appears to step through it. In fact, the caster becomes invisible (as the invisibility spell, pg. ###) and moves at 2x normal speed for the spell’s duration. The door appears to connect to a dark tunnel or a 10’ cubic room. If another creature tries to follow the caster through the door, it takes 2d6 force damage and is knocked prone. 

Cartoon shenanigans, or a bit of stage magic. 

10. Shadow Magic
Illusionist 5
R: varies T: varies D: 0
The caster casts an umbral copy of a spell chosen from the list below:
Cone of cold (pg. ###)
Fireball (pg. ###)
Lightning bolt (pg. ###)
Magic missile (pg. ###)
Others similar spells be allowed at the GM’s discretion. Intelligent creatures may Save, in addition to any Saves prompted by the spell. If a creature passes, the spell deals a maximum of [caster level] damage to them. 

You can be a Magic-User too, Illusionist! Look at all that flexibility. Don't be sad. They're almost as good as brand-name spells at half the price.

11. Shadow Monster II
Illusionist 5
R: 50’ T: point D: [caster level]+4 rounds
As shadow monster I,  but the creatures have 1d4 HP per HD and deal full damage.

Look, numbered summon spells are rarely going to blow your socks off.

12. Visitation
Illusionist 5
R: unlimited T: person D: 0
A ghostly figure appears before target person known to the caster. The figure takes the form of a person from the target’s past. It conveys a message of up to 25 words, plus thematic gothic intonations and warnings. The target does not need to respond, and may Save to detect the false nature of the visitation.

The 25-word limit is standard for messaging spells, as it forces players to really think about their words. This spell gives the GM license to ad-lib. The message "Revenge your father's murder" or "You shall be king of Scotland" get suitable punch-ups in Shakespeare.

Tom Kidd

Level 6

1. Acid Fog•
Illusionist 6
R: 120’ T: point D: [caster level] + 1d4 rounds
Creates 2x 10’ cubes of opaque fog per [caster level]. The fog is as thick as cotton wool and heavier than air. Creatures in the fog move at 1/10th normal speed, cannot make melee attacks, and take 1d6 acid damage per round. It erodes non-magical objects and kills vegetation. Strong wind does not affect the fog.

A short-duration wall, but with a nasty effect, especially if people were expecting regular fog. I remember a player cast this in a library once. Not a good plan. Banned forever.

2. Eerie Terrain
Illusionist 6
R: 120’ T: area D: permanent
Affects [caster level]x2 10’ squares. The caster cloaks the area in an illusion. While the underlying structure of the area remains the same, the illusion adds menacing shadows, dust, cobwebs, unearthly winds, and other minor effects. Creatures must Save when they enter the area for the first time or move through it at ½ speed. Creatures unaware that the area is cloaked in an illusion automatically fail Saves against fear. 

The first truly permanent illusion effect on the list. It's similar to the canonical spell vacancy, but with different effects. While I'm not normally a fan of permanent spells, this seems very Illusionist. Turn any house into a haunted house. Turn a haunted house into a properly nightmarish zone.

3. Geas*
Cleric 5, Illusionist 6, Magic-User 6
R: touch T: creature D: permanent
Target intelligent creature that can understand the caster must Save or carry out a quest of the caster’s choice. The quest cannot lead to certain death, but moderate peril is acceptable. Failure to obey causes the creature to sicken and die over 1d4 weeks. The quest must be relatively simple and thematic.

Reversed: Remove a geas and learn who cast it.

The canonical illusionist equivalent is dream quest, but that's just geas with extra steps. Sauce for the geas is sauce for the gander. Heh heh heh.

4. Impersonate
Illusionist 6   
R: touch T: creature D: [caster level]x10 minutes
The target takes on the appearance of another person or creature of approximately the same size. Voice, mannerisms, odour, and gait are copied. The target can speak and understand any languages known by the impersonated creature, but gains no additional knowledge. Illusionary equipment is also provided, but vanishes when the spell ends. The illusion ends if the target takes more than 5 damage. This spell requires but does not consume an item or bodily sample (hair, blood, etc.) of the target.

The damage buffer is very handy. Clever people might know that illusions pop when dealt damage and test it with a bit of mild stabbing.

5. Phantasmal Feast
Illusionist 6   
R: 60’ T: point D: [caster level] hours
An elaborate illusionary feast appears. It appears to feed [caster level]x2 people. The caster may specify individual dishes, but the spell defaults to meals appetizing to people within 60’. Illusionary serving dishes and tablewear is also created. The food looks, smells, and tastes real, but provides no nutrition. The caster learns the true name of any person that eats the food. For the spell’s duration, any creature that eats the food automatically fails Saves against illusions created by the caster, and has a -4 penalty to all other Saves. Additionally, the caster may cause any number of creatures of 2 HD or below that eat the food to fall asleep (as the sleep spell, pg. ###).

Do not eat the goblin fruits. Or do. I'm not in charge of your life. I just write these spells. Anyway, this is a properly fey effect. This could conceivably be a ritual spell with a long casting time, like create food and drink, but what self-respecting Illusionist wouldn't summon a meal from thin air with a flick of the wrist?

6. Pseudocide
Illusionist 6, Magic-User 6   
R: 0 T: self D: 0
May cast this spell as a reaction. The caster teleports up to 50’ in any direction and turns invisible for 2d6 rounds or until they take a hostile action. A dead fleshy duplicate is left behind, clad in facsimiles of the caster’s clothes and items, when the caster teleports. The duplicate will not pass close inspection.

This spell lets the caster effectively negate one incoming attack (if they react to the attack itself and not to being dealt damage.. It's a better fit for the MU spell list, where duplication effects are less common, but it's such a fun concept that I felt I had to give it to the Illusionist too. I think the name is tied with insubstantiate for "made-up words that succinctly describe a spell."

7. Repeat Spell
Illusionist 6, Magic-User 6   
R: 0 T: self D: 0
The caster may immediately cast a lower level spell that they previously cast within 24 hours, as though they had prepared that spell instead of repeat spell. All costs, targeting restrictions, etc. still apply.  

Another infrastructure spell. It's not exciting, but it adds flexibility to high-level casters. This spell nearly breaks my "would be good as a wand or scroll" rule for the Treasure Overhaul spell lists, but it's a powerful caster-boosting item.

8. Shade
Illusionist 6
R: 0 T: self D: [caster level] rounds
The caster vanishes and is replaced by 2 illusory duplicates. The duplicates may immediately take their turns. They are destroyed if they take any damage and cannot cast spells or use magical or consumable items. They can move, speak, open doors, pick up items, and make melee attacks with mundane weapons. When the spell ends, both duplicates vanish, and the caster returns, occupying the space formerly occupied by a duplicate. If a duplicate is destroyed before the spell ends, the caster immediately returns, occupying the space of the other duplicate. If both duplicates are destroyed simultaneously, the caster may choose which space to occupy.

While I'll take credit for this spell as written, it's not an original idea by any means. It's in all sorts of RPGs, video games, etc. I think this implementation is fairly elegant. It's a mirror version of project image. I once wrote and used a version of this spell that created 2d6 copies instead of 2, but it ended up being far too chaotic.

9. Shadow Monster III
Illusionist 6
R: 50’ T: point D: [caster level]+4 rounds
As shadow monster I, but the creatures have 1d8 HP per HD, deal full damage, and have illusory copies of supernatural abilities. These abilities cannot deal damage or create permanent effects (see phantasmal force, pg. ###). The GM may wish to track “damage” from the abilities against a creature’s HP, but actual HP is not reduced. A creature “disintegrated”, “teleported”, or “turned to stone” by a Shadow Monster is merely paralyzed for 1 minute.

Hooray for incremental upgrades! In the standard version, the supernatural abilities are provided at the lowl-level version, but that requires a lot of GM rulings and partially replaces phantasmal force. The Illusionist can probably min-max the summoned creatures, but they're still only illusions. Wishes granted by exclusionary Djinn are not real. Is flight granted by an illusionary Pegasus real, or does a character just believe they're flying very slowly at ground level? 

10. True Seeing*
Cleric 5, Illusionist 6, Magic-User 6   
R: 0 T: self D: [caster level] rounds
The caster sees through illusions, sees invisible and ethereal creatures, and sees the true form of shapeshifters, transformed, or enchanted creatures.

Reversed: Touched living creature must Save or see the attributes of other creatures as their opposite (beauty as ugliness, deadly intent as good cheer, etc.) for [caster level] rounds.

I keep flip-flopping between "True Seeing" and "True Sight." The reversed version is amusing but very situational. It could be very useful if the GM rules that a dragon sees a thief as a supplicant.

Level 7

1. Astral Spell
Cleric 7, Illusionist 7, Magic-User 9   
R: 0 T: self D: [caster level] hours
The caster projects their mind into the astral plane (or local equivalent). Their body remains behind in a state of suspended animation. There is a 50% chance that this spell ends if the body is damaged. While projecting, the caster is effectively an intangible, invisible, flying duplicate. The caster may cast spells from the projection, but for each spell cast, there is a cumulative 5% chance that this spell ends and the caster returns to their body. The projection moves at 100 miles per hour or 1,000 feet per round.

Another condensed classic. I've never found this spell particularly compelling. I may clarify that the projected form can still be targeted (if someone can spot it), and that it isn't immune to magic damage. Projecting into your archenemy's lair is unwise. Projecting near PCs that can see invisible creatures and are willing to take hostages is also unwise.

2. Drama
Illusionist 7
R: 240’ radius T: area D: concentration+2d6 rounds
The caster twists the nature of reality, turning the world into a stage. Creatures, projectiles, and effects cannot cross the spell’s radius in either direction.
Within the spell’s area:
•All damage becomes non-lethal damage.
•If a creature would die, it is instead rendered unconscious until the effect ends.
•Fire becomes red paper, acid green water, etc.
•Intelligent creatures must Save or explain their motives before taking any action.
•Speech becomes overwrought, poetical, emotional, rhetorical, fanciful, or satirical.
•All creatures believe that they are in a play, or some other unreal and harmless activity before an imagined audience.
Additionally, the caster creates a beam of light that illuminates a point within range. It cast light as a torch. The caster can move the beam to any point within range each round.

I think this is a fairly interesting capstone ability for the Illusionist. If you're going to pretend to pretend to cast spells, then a high-level spell should be even more meta. The duration is the only thing I'm struggling with. Minutes makes it from a scene into full play but completely dominates an encounter.
"You die a thousand casual deaths - with none of that intensity which squeezes out life... and no blood runs cold anywhere. Because even as you die you know that you will come back in a different hat. But no one gets up after death - there is no applause - there is only silence and some second-hand clothes, and that's death." - Rosencrantz and Guildenstern are Dead.

3. Invisibility, Mass
Illusionist 7, Magic-User 7   
R: touch T: creature D: 1 hour
Target creature, and all creatures within 50’ when the spell is cast, are invisible. The area moves with the targeted creature. The effect ends for a creature in the area if the creature takes a hostile action or leaves the area. It ends for all creatures if the targeted creature takes a hostile action. Clothing and carried items are also invisible.

Another improved version of a lower-level spell.

4. Mirage
Illusionist 7
R: line of sight T: point D: varies
Must be cast out of doors. An illusionary scene appears on the horizon. The caster may create a distant city, the dust of an approaching army, a refreshing lake, or any other vista imaginable. Creatures within 6 miles when the spell is cast can see the mirage, but it always appears to be just out of reach for the spell’s duration, though creatures must Save to notice its shifting location. The effect lasts until the caster dies or casts this spell again.

Not a powerful spell by any means, but the ability to delude a whole region could be useful. Are you racing a rival party for the Lost Temple of Filboid Studge? Good luck finding it with this spell active.

5. Permanent Illusion
Illusionist 7   
R: 240’ T: point D: permanent
As phantasmal force, but permanent. The illusion is sill destroyed if it is dealt damage.

Another permanent spell. Bear in mind that this is the starter version of phantasmal force, the glassy, silent, and unconvincing one. Still, permanent glassware, servants, or treasure could be useful.

6. Prismatic Spray
Illusionist 7
R: 70’ cone T: area D: 0
Multicoloured rays fire from the caster’s outstretched hand. Roll for each creature in the area. 1d10:
1. Red. 3d6 fire damage, Save or set on fire.
2. Orange. 3d6 bludgeoning damage, Save or prone.
3. Yellow. 3d6 lightning damage, Save or deafened.
4. Green. 3d6 acid damage, plus 1d4 on subsequent rounds or until washed.
5. Blue. 3d6 cold damage, Save or be frozen in place in a block of ice.
6. Indigo. Save against poison or die.
7. Violet. Teleported 1d10’x10’ horizontally in a random direction and stunned for 1d6 rounds.
8. Unlight. Disappear for 1d6 rounds. If a summoned creature, Save or be banished.
9. Struck twice. Roll 2 d8s.
10. Struck thrice. Roll 3 d8s.   

I modified this spell significantly. Yes, the old "save or paralyzed" "save or go insane" and "save or be turned to stone" are all nicely categorized by saving throw, but they're not particularly interesting in play. "Go insane" is such a difficult effect to adjudicate (let alone adjudicate tastefully) that I think it's fine to omit. Being trapped in a block of ice is more fun than being turned to stone, and fits the elemental theme. With chromatic orb, the Illusionist already has reliable save or die effect (as the comments pointed out in the last post), so this spell should do something different.

The area of prismatic spray also varies considerably between editions. I could make it a 70' line 10' wide to keep it closer to AD&D's version, but a wide cone, for a max-level spell slot, feels fair to me. It's a spray. Friend and foe alike should beware.

7. Prismatic Wall
Illusionist 7
R: 70 T: area D: concentration + [caster level] rounds
Creates a glowing wall of light, summoning a 10x10’x1’ thick panel per [caster level]. The caster can mould the wall into any shape. The wall does not need to be vertical or attached to a solid surface, but it cannot intersect creatures or objects. It is not solid. It casts light as a torch and is immune to damage. Creatures that attempt cross the wall, or end their turn adjacent to it, are struck by the prismatic ray spell.

It's a wall that isn't a wall, but it's also a wall you really don't want to be near. The caster can use it to create a protective dome, but the effect applies to all creatures, not just hostile ones. The projectile-blocking effects of a prismatic sphere (not included in this spell list) aren't included. Prismatic sphere always felt like a spell that was written without at-table resolution in mind. Too much AD&D rock-paper-scissors design. 

8. Shadow Walk
Illusionist 7
R: 10’ T: area D: 0
This spell can only be cast in deep shadow. The caster and up to [caster level] willing creatures teleport to a shadowed location known to the caster, anywhere. For each creature past the first, there is a cumulative 1% chance the destination is an unknown shadowed area of the GM’s choice. Areas that hold special meaning for the targets (positive or negative) will tend to be selected. 

A caster should have a good long-range multi-target teleportation spell, and this qualifies. I'm not totally pleased with "GM picks" effects, but the percentile roll introduces some tension, and the "shadowed area" prompt might help the GM come up with a good inconvenient location.

9. Sunbeam
Cleric 6, Illusionist 7, Magic-User 6   
R: 60’ cone T: area D: 0 / concentration
Pure sunlight flashes from the caster’s hand. Creatures in the area take 3d6 damage and must Save or be blinded for 1d6 rounds. Undead creatures take 6d6 damage instead. As long as the caster concentrates, their hand casts sunlight as a torch.

Aside from the obvious use as an "Take that, Dracula!" spell, I've also seen players use sunbeam to signal over great distances and lure plant-based creatures to their doom. In terms of pure damage it's less impressive than prismatic spray, but it's much more reliable. It could be replaced if there was a suitable candidate. If you can think of one, leave a comment.

10. Time Stop
Illusionist 7, Magic-User 9
R: 0 T: self D: [caster level] rounds
The world stops. From the caster’s point of view, creatures and enchantments become frozen smoke-shrouded shapes. They cannot affect the caster, or be affected by them, for the spell’s duration. The caster may move and interact with objects normally, but moving any object heaver than a sword requires a Strength test. Spellcasting is not possible.

This spell is here for two reasons. First, I'm pleased with it. It's hard to write a time stop spell that works the way people expect it to work. Second, it fits the theme established with accelerate time. How did that coin get in your pocket? How did the magician know what you'd written on the card? Time stop.

João Bragato

Final Notes

The Illusionist doesn't get access to the top-tier Magic-User game-breaking powers like wish and true polymorph. Instead, they get access to spells that change the nature of encounters, enable ludicrous schemes, and cause chaos. 

The general Illusionist plan is to throw out a few non-concentration spells with multi-round durations, then start a concentration spell to add another layer of madness. Combining spells is crucial. Use hypnotic pattern, improved to lure creatures into a pit concealed with an illusion, or into a prismatic wall. Create distracting shadow monsters, then turn invisible and run. Use eerie terrain to make phantasmal killer or emotion even more deadly.

If you have strong feelings about any of the changes I've made, post in the comments and I'll see what I can do. I changed a few spells from the previous post based on suggestions in the comments. 

2024/09/02

OSR: Illusionist Spell Rewrites (Treasure Overhaul/AD&D)

The Treausure Overhaul is going to include spells. They're too useful for treasure design. It's tricky to make a systemless OSR book that includes wands, scrolls, artifacts, and other spell-related items without providing spells. 

This requires a bit of class design. Here's a peek behind the scenes at the process, using the Illusionist level 1-3 spells as an example. Old-school games trend towards lower levels, so I'm using them as an example. 

Sherbakov Stanislav


Notes On The Illusionist Class

The Illusionist is odd on a fundamental level. In an RPG, you pretend to do things. When you play an Illusionist, you pretend to pretend to do things. Do you want to pretend to cast fireball or pretend to pretend to cast fireball? It's terribly meta.

It is difficult to argue that the Illusionist, in most OSR games, is a weaker Magic-User. Sure, illusions are versatile, but the Magic-User has a host of tools that actually do things. You can bloviate about the versatility of phantasmal force all you'd like, but at the end of the day, how many players choose Illusionists? They're rarer than Druids! More crucially, how many play an Illusionist twice?

The core concepts are:

  • Illusions. Things that appear real but are not real. 
  • Concentration-based spells.
  • Trickery.
  • Stage magic.

References

While writing the spell lists in the Treasure Overhaul, I'm referencing a number of books. If I'm writing a generic spell, it's important to ensure it does what the reader expects it to do.

The four major references are like the corners of a map. If the spell I've written doesn't fall somewhere between them, then I've either done something wrong or made a deliberate choice to strike out for parts unknown.

1. The LBBs (+Greyhawk +some supplemental materials when necessary). The spell summon floogle reads "Summon 1 floogle."

2. AD&D (+Unearthed Arcana). The spell summon floogle reads "You summon 1d4-1 floogles of no more than caster level / 2 HD for 2d6+4 turns. They appear on the nearest horizontal surface within 30'. The floogles obey the tallest person within 120' or anyone wearing a helmet, though helmets created by the illusory helmet spell do not count. The material components of this spell are a slide whistle and a small pot of apricot jam." Lots of cruft between the player and the floogle. 

3. Old School Essentials. Distilled and popular OSR. An attempt to clean up some of AD&D's more peculiar and ambiguous sections to produce compact spell lists. Typically, I'll read the AD&D version of a spell, rewrite it, then check OSE to see how Gavin Norman approached the same problem.

4. D&D 5E. Shock, horror, etc, but hear me out. 5E design distills spells in a particular way. It is sometimes useful to see what pitfalls and edge cases were "fixed" over the years.

I'll also check blog posts, forums, and old magazines for particularly tricky spells. I can't read everything, let alone digest it. I can't pretend to possess some sort of game designer ivory tower omniscience, even if it would help sell books. I'm just muddling through with intuition, experience, and vague memories of things that worked and things that did not work. 

I also have to balance canonical spells with personal preferences. What can I tweak? What can be improved? What can be compressed? Can this spell be conveyed to a player and written down in a comprehensible format on the back of a scrap of paper? If a group uses this book alongside another book, will contradictions slip under the radar or cause insurmountable problems? There's no way to write a general-purpose spell list without causing some problems. The goal is to make consistent choices towards utility.

Justin Cherry

Canonical Illusionist Spell Lists

The OD&D spells are taken from Peter Aronson's 1977 Wild Hunt #19 article, the final pre-AD&D Illusionist version. AD&D spells from Unearthed Arcana are in italics.

Level 1 OD&D (Aronson) AD&D OSE
1
Audible Glamer Auditory Illusion
2 Change Self Change Self Glamour
3
Chromatic Orb Chromatic Orb
4 Colour Spray Colour Spray Colour Spray
5
Dancing Lights Dancing Lights
6 Darkness Darkness
7 Detect Illusion Detect Illusion Detect Illusion
8 Detect Invisible Detect Invisibility
9 Gaze Reflection Gaze Reflection
10 Hypnotism Hypnotism Hypnotism
11 Light Light Light (Darkness)
12 Phantasmal Forces Phantasmal Force Phantasmal Force
13
Phantom Armour
14
Read Illusionist Magic Read Magic
15
Spook Spook
16 Wall of Fog Wall of Fog Wall of Fog

Mirror Image


Ventriloquism





Level 2 OD&D (Aronson) AD&D OSE
1
Alter Self Quasimorph
2
Blindness Blindness / Deafness
3 Blur Blur Blur
4 Deafness Deafness
5 Detect Magic Detect Magic Detect Magic
6
Fascinate
7 Fog Fog Cloud
8
Hypnotic Pattern Hypnotic Pattern
9 Improved Phantasmal Forces Improved Phantasmal Force Improved Phantasmal Force
10 Invisibility Invisibility Invisibility
11 Magic Mouth Magic Mouth Magic Mouth
12
Mirror Image Mirror Image
13
Misdirection False Aura
14
Ultravision
15
Ventriloquism
16
Whispering Wind Whispering Wind

Rope Trick


Dispel Illusion


Level 3 OD&D (Aronson) AD&D OSE
1 Continual Darkness Continual Darkness
2 Continual Light Continual Light
3
Delude
4
Dispel Illusion Dispel Illusion
5 Fear Fear Fear
6 Hallucinatory Terrain Hallucinatory Terrain Hallucinatory Terrain
7 Illusionary Script Illusionary Script
8 Invisibility 10' Radius Invisibility 10' radius Invisibility 10' Radius
9 Non-detection Non-detection Nondetection
10 Paralyzation Paralyzation Paralysation
11
Phantom Steed Phantom Steed
12
Phantom Wind
13
Rope Trick Rope Trick
14 Spectral Forces Spectral Force Spectral Force
15 Suggestion Suggestion Suggestion
16
Wraithform Wraithform

Phantasmal Killer
Blacklight

Dispell Exhaustion


Color Bomb


Dreams

 

Canonical Spell List Observations

Aronson's list has some spells (mirror image, ventriloquism) at level 1 instead of AD&D/OSE's level 2, and some (rope trick, dispel illusion) at level 2 instead of AD&D's/OSE's level 3. Making ventriloquism a level 1 spell makes a lot of sense; it's really not worth a 2nd level spell slot. Mirror image is at level 1 is a minor tweak, but one that gives the Illusionist some much-needed early damage resistance. The real meat-and-potatoes of level 1 is phantasmal force, which gets several paragraphs of text below.

OSE combines some spells into one (deafness/blindness, light/darkness). I like modular or reversible spells. It keeps the spell list compact and it gives the player more options. If a spell has an intuitive reversal, it should be included (even if the reversed version is less useful than the prime version). Yes, in some systems, Illusionists don't get reversible spells, but that feels unnecessarily cruel. 

The Illusionist spell list has many spells that require concentration. Any spell that doesn't require concentration is therefore slightly more powerful. Cast a few of those, then set off your centrepiece spell. 

The Treasure Overhaul Illusionist Spell List (1-3)

1d20 Level 1 Level 2 Level 3
1 Audible Glamer Become Delicious Butterfly Hurricane
2 Chromatic Orb Blur Colour Bomb
3 Colour Spray Charm Person Conceal Intent*
4 Detect Invisibility Compulsive Laughter Daydream
5 Disguise Conceptual Blade Dispel Illusion
6 Faerie Fire Conspicuous Ritual Fear
7 Fog Darkvision Flare
8 Fool’s Gold Deprive Sense* Glitterblast
9 Hypnotism Detect Magic Hallucinatory Terrain
10 Imaginary Pit Escapolgy Hold Person
11 Light* Feign Death* Invisibility, 10' Radius
12 Mage Hand Hypnotic Pattern Misdirect Scrying
13 Magic Aura Invisibility Mundanify
14 Mirror Image Locate Object* Phantom Steed
15 Mirror Shield Magic Mouth Phantom Wind
16 Phantasmal Force Mirror Object Space Swap
17 Read Magic Phantasmal Force, Improved Splitting Image
18 Spook Silence Suggestion
19 Synesthesia Sleight of Hand Unlight
20 Ventriloquism Whispering Wind Wraithform

In the book, all spells are arranged alphabetically. For this post, I've split them by level. Commentary is indented and in purple. Spells with names in blue are new. I can't guarantee they're completely original (given the sheer number of spells that have been published and the number of spells I've read over the years), but they weren't written with any reference in mind.  

Ritual spells will go on their own list. I've moved rope trick there. It's a great spell if the players have 10 minutes to set it up during turn-based dungeon exploration, but it's a real hassle in combat. There are some spells you can cast while an kobold is trying to gnaw off your legs, and some spells you can't, and rope trick is, in my opinion, firmly in the latter category. Separating rituals makes treasure design easier. Do you really want to find a stave of rope trick or a wand of find familiar, given the other options? 

Level 1

1. Audible Glamer
Illusionist 1, Magic-User 2   
R: 120’ T: point D: 1 minute
A sound emerges from the designated point. It can be a piece of music known to the wielder or a sound effect (battle, roaring flames, whispering, etc.), but cannot be intelligible speech. Intelligent creatures can Save to detect the false nature of the sound. At maximum volume, the noise is audible within 120’.

I'm not entirely sold in the name. OSE's "auditory illusion" feels clinical, but audible glamer is only one step from ye olde audibyle gygaxian glamer.
2. Chromatic Orb
Illusionist 1   
R: 30’ T: creature D: 0
The caster makes a ranged attack roll. Target gains no bonus from armour. On a hit, choose one of the effects below (limited by [caster level]):

[C.L.] Colour Dmg. Effect
1 Pearl 1d4 Target glows for 2d6 rounds.
2 Ruby 1d6 Melts a 3’ cube of ice.
3 Flame 1d8 Sets things on fire.
4 Amber 1d10 Save or blind 2d4 rounds.
5 Emerald 1d12 Save or reek 1d4 hours.
6 Turquoise 2d8 Save or drop 1d4 items.
7-9 Sapphire 2d4 Save or paralyzed 4d6 rnds.
10-11 Amethyst - Save or turn to stone.
12+ Ashen - Save or die.

This spell requires but does not consume a gem of the appropriate type, or a diamond, worth 100gp.

Chromatic orb was clearly a spell written without page restrictions in mind. I'm pleased that I managed to compress it to a manageable level while retaining the core weirdness. Some edge cases and stacked effects had to be cut, but so it goes.
3. Colour Spray
Illusionist 1   
R: 30’ cone T: area D: 0
Prismatic dust sprays from the caster’s hand. 1d6 sighted creatures in the area must Save or be affected based on their HD:
•Under [caster level]: Unconscious for 2d8 rounds.
•Equal to Equal+2: Blinded for 1d4 rounds.
•Equal +3 or more: Stunned for 1 round.

The reliable classic. When in doubt, colour spray and run. 

4. Detect Invisibility
Illusionist 1, Magic-User 2    
R: 30’ radius T: self D: 10 minutes
Invisible, ethereal, and out-of-phase creatures are visible. The caster can see through illusions.

It's a detect spell. What more do you want? A 10 minute limit instead of [caster level] round-based math makes the spell more useful for exploration.

5. Disguise
Illusionist 1   
R: touch T: creature D: 10 minutes
The target takes on the appearance of another person or creature of approximately the same size. Illusionary equipment is also provided, but vanishes if dropped. The illusion ends if the target takes damage. 

Having an illusionary shapechange spell makes a nice contrast to the Magic-User's more dangerous polymorph shenanigans. Obligatory Oglaf reference (NSFW).

6. Fairie Fire
Druid 1, Illusionist 1    
R: 60’ T: creature or object D: 10 minutes
Up to 3 creatures or objects are outlined in harmless flickering flames. Attacks against them gain a +2 bonus to hit. The flames are visible in darkness.

This is a druid-only spell in AD&D, but it feels like a useful Illusionist tool as well. The weird casters have to stick together.

7. Fog
Druid 2, Illusionist 1
R: 60’ T: point D: varies
Creates a 10’ cube of opaque fog per [caster level]. The fog is heavier than air. It lasts 1 hour in still air or 10 minutes in a strong wind.

Combining all the fog spells into one long-duration spell that scales with [caster level] makes sense. It's fog. It's not charm person or magic missile. It's a "trade one set of problems for a different set of problems" spell, which is always delightful, but it's not worth two or three different spells with slight variants on range, effects, duration, and movement. A special spell that makes a fake cloudkill" is useful in AD&D's imagined game of rock-paper-scissors-improved paper-improved rock-etc, but regular old fog is, in practice, much more fun.

8. Fool’s Gold
Illusionist 1, Magic-User 2
R: 10’ T: area D: 6 hours
Affects a 1’ cube per [caster level]. Assume 4,000 coins fit in a 1’ cube. Metallic items are enchanted to appear to be gold. Intelligent creatures who inspect the items can Save with a penalty equal to [caster level] to detect the deception. If the items are damaged, there is a 50% chance the spell ends.  

This is a very obvious "give the players rope to hang themselves with" spell. By all means, engage in shenanigans. Bribe monsters. Cheat merchants. Get into trouble.
9. Hypnotism
Illusionist 1
R: 30’ T: creature D: [caster level]+1 rounds
The caster speaks a short, simple, and reasonable command to 1d6 creatures within range. The creatures must Save or obey. Targets must be able to hear and understand the caster. The command must be a plausible course of action. 

I might revisit the wording on this spell. I don't want to go overboard with restrictions and guidelines, but I also want the spell to be easy to adjudicate. At first, I thought I'd replace it with charm person, but it is genuinely niche and interesting enough that I think I'll have to include it.  
10. Imaginary Pit
Illusionist 1
R: 120’ T: creature D: 0
Target creature experiences the illusion of falling into bottomless pit filled with accusatory voices. Save negates. If it fails, the creature is stricken with a deep depression (if sapient) or lethargy (if mindless) for [caster level] hours. This may alter its level of hostility or prompt a new reaction roll.

This spell is strictly worse phantasmal force, but it enables bluffing and other wizardly schemes. Cloudkill just kills you. What the heck did that spell do? Was I dead? Am I alive now? What is reality?

11. Light*
Cleric 1, Illusionist 1, Magic-User 1   
R: touch T: object D: 1 hr+10 mins per [caster level]
Target object casts light as a torch.
Reversed: Target object casts darkness instead. This darkness does not affect magical light.

Light, of all spells, should be a simple resource calculation. A backup non-flammable light source and space in a character's inventory in exchange for a spell slot.

12. Mage Hand
Illusionist 1, Magic-User 1   
R: 30’ T: point D: concentration, up to 1 minute.
Creates an invisible hand. It must remain within 30’ of the caster, moves at 30’ per round, follows the caster’s hand motions, and is as strong two of the caster’s fingers.

Mage hand is not a traditional Illusionist spell, but it is a powerful enabler of shenanigans, and it fits the stage magician theme (if not the "do things without actually doing them" theme). I am not responsible damage caused while testing what you can hold between two fingers.

13. Magic Aura
Illusionist 1   
R: touch T: object D: permanent
Target object weighing no more than 500lbs detects as magical. Close scrutiny while using detect magic (pg. ###) will reveal the deceptive nature of this spell.

This is usually a magic-user spell as well, but, for Treasure Overhaul purposes, I had to move it to Illusionist only. Is this likely to cause trouble? No. Not at all. Trickery is the Illusionist's game, and making objects appear magical seems like Illusionist-specific magic.

14. Mirror Image
Illusionist 1, Magic-User 2   
R: 0 T: self D: 1 hour
An illusionary duplicate of the caster appears. It moves with, imitates, and blurs the caster. For every 3 [caster levels] past the first, they may create 1 additional duplicate, to a maximum of 3 duplicates. If a single-target attack would hit the caster, there is a chance it hits a duplicate instead, destroying it. Roll 1d20 and consult the number of duplicates below:
•One Duplicate: Hit on an 11 or more.
•Two Duplicates: Hit on an 8 or more.
•Three Duplicates: Hit on a 6 or more.

I stuck mirror image at level 1 and tweaked the duration. OD&D has 1 hour, AD&D has 2 rounds per level, OSE has 1 hour. I like a 1 hour duration. It lets the Illusionist form a barbershop quartet.
15. Mirror Shield
Illusionist 1   
R: 0 T: self D: concentration+1 round
May cast this spell as a reaction. An reflective plate of force appears in front of the caster. It is 5’ in diameter, reflects gaze attacks and light, and may reflect some light-based spells at the GM’s discretion. It does not prevent damage, block missile attacks, or block line of sight to the caster for targeting purposes.
I changed the name from gaze reflection to make the implied effect more versatile. Spells that can be cast a reaction are another Treasure Overhaul tweak. There aren't many of them, but they encourage a caster to memorize less optimal spells for some out-of-turn surprises. Sure, you can use it to reflect gaze attacks, but you could also spook beasts with a mirror or reflect lasers. Surprising amount of lasers in D&D.  

16. Phantasmal Force
Illusionist 1, Magic-User 2   
R: 240’ T: point D: concentration, up to 1 minute
An illusion smaller than a 20’ cube appears. The illusion is silent, slightly glassy, and is destroyed if it is dealt damage. The caster can create any contiguous scene, creature, or effect imaginable. Creatures can Save to see through the illusion. An illusionary monster appears to deal damage, but no actual damage is inflicted. The GM may wish to track “damage” against a creature’s HP, but actual HP is not reduced. A creature “killed”, “squashed flat”, or “turned to stone” by an illusion is merely paralyzed for 1 minute.

Ah, phantasmal force, probably the most controversial and confusing spell in the Illusionist class. Over the years, more ink has been spilled over this spell than any other. It's the Jarndyce v Jarndyce of the OSR. This is my stance. No actual damage, just implied damage. Save up front, but no restrictions on effects (anything a caster can imagine, not just things they've seen before). 

"Paralyzed for 1 minute" can equal dead if the PCs are quick about finishing off downed combatants. The spell is "Save or believe", not "Save to disbelieve", which speeds up resolution and removes a lot of ambiguity. 

The improved version increases the size of the illusion, adds smells, sounds, and textures, and imposes a penalty to Save. The "dealt damage" requirement means merely touching the scene isn't enough (which eliminates a lot of back-and-forth with the GM over what counts as touching). You have to give it a solid whack (as an action). I prefer to think of illusions as holograms and not mental images. It makes resolving them much easier.

 Phantasmal force, as written in AD&D and OD&D, also consumes the general purpose illusion design space. Any specific or restricted illusion can, most of the time, be replicated by phantasmal force. The only real restriction is the duration. Frankly, this spell is a mess. Every use starts a negotiation with the GM. It dominates the scene. 

I could condense it, issues and all, but if I'm going to write a book of good treasures, and those treasures include spells, I'm obligated to try and write good spells.

Side Note: I'd always assumed the "force" in "phantasmal force" was "violence, action, or momentum", but it's entirely possible, given OD&D roots, that it means "an armed band of warriors." A phantasmal squad of archers. A wargame unit.

17. Read Magic
Illusionist 1, Magic-User 1   
R: 0 T: self D: 10 minutes
The caster can read and interpret magical text, including scrolls, spell books, arcane inscriptions, etc. Once read, a work remains intelligible.

I'm not a huge fan of this spell from a game design point of view, but I'm not willing to cut it from the list. It's infrastructure.  

18. Spook
Illusionist 1
R: 120’ T: creature D: 0
Target creature must Save or perceive the caster as a terrifying creature or effect. The caster and other creatures do not know what the target sees. On a failed Save, the target flees for [caster level] rounds. The creature gets new Save each round. On a successful Save, the spell ends.

A single-target fear spell, but with a fun twist. "What is this creature afraid of, and how do I convey that fear?" is a fun low-consequence prompt for a GM.
19. Synesthesia
Illusionist 1
R: touch T: creature D: [caster level]+1d4 rounds
Target living creature’s senses are confused and mixed. Colours evoke sounds. Tastes evoke flashes of light. The target must Save each round or be stunned.

An ongoing multi-round stun effect isn't too powerful at level 1, but it is also a non-damaging spell, for all those situations where someone needs to be inconvenienced but not massacred.

20. Ventriloquism
Illusionist 1, Magic-User 1   
R: 120’ T: point D: concentration+1d4 rounds
The caster’s voice appears to come from the chosen point. 

Nobody is excited about ventriloquism alone, but it is an amusing distraction. It also combines well with other spells in an unspectacular way.
Devin Becker

Level 2

1. Become Delicious
Illusionist 2   
R: touch T: creature D: [caster level] hours
Target creature smells delicious. The smell radiates 30' in calm air, but can spread via wind or leave a trail. Sapient creatures can usually resist the urge to eat the target, but beasts and ravenous creatures must Save or select the spell's target as their primary attack target. Insects will be attracted to the target for the spell's duration.
I love this spell. I've run it in games for years and it always leads to great schemes. Step 1, fill a pig with poison. Step 2, take it to the top of a rickety tower. Step 3, cast this spell. Step 4, wait for the dragon to arrive. The ghoul ambush + disposable hireling combo is another rather grim use case.
2. Blur
Illusionist 2
R: 0 T: self D: 10 minutes
The caster’s precise location is smeared and distorted by flickering illusions. The first attack a creature makes against the caster has a -4 penalty. All subsequent attacks the creature makes have a -2 penalty. The caster gains +1 to Save against magic
Because it's a penalty to hit and not a bonus to AC, blur stacks with mage armour (not on the Illusionist list, but common enough). It also stacks with mirror image.

3. Charm Person
Druid 2, Illusionist 2, Magic-User 1   
R: 120’ T: person D: permanent
Target person must Save or regard the caster as a good friend. The target may Save again to negate:
•Int. 3-8 (below average): each month.
•Int. 9-12 (average): each week.
•Int. 13-18 (above average): each day.

Replaces the functionally identical fascinate spell. 
4. Compulsive Laughter
Illusionist 2, Magic-User 2   
R: 50’ T: creature D: 1 round
Target sapient creature must Save or fall prone and helplessly laugh for 1 round. If it failed its Save, on the subsequent round, the target also has -2 penalty to attack rolls and Saves.
This should probably be a 1st level spell, but canonically it's 2nd level. Should I move it to where I feel it belongs, or leave it where readers might expect to find it? These are the perils of systemless design.
5. Conceptual Blade
Illusionist 2    
R: 0 T: self D: concentration + [caster level] rounds
Conjures the illusion of a smoking black sword in the caster’s hand. Damage varies based on a struck target’s intelligence:
•Mindless / objects: no damage.
•Non-sapient: 1d4+1 non-lethal damage.
•Sapient: 1d6+1 non-lethal damage.
If a sapient target is in an altered state (drunk, drugged, panicked, very credulous), they must Save. If they fail, the sword deals is lethal damage instead.
Surprise, it's a wizard with a sword! A very difficult-to-kill wizard with a sword thanks to blur and mirror image and general illusionist tricks. 
6. Conspicuous Ritual
Illusionist 2
R: 0 T: self D: concentration
This spell appears to be a potent and dangerous ritual, but is merely theatrical. Spellcasters may Save to detect its nature. The caster may not move while concentrating. Effects vary with the number of rounds spent concentrating:
•1: Floating runes, shimmering circles.
•2: Arcs of light and false fire. Casts light as a torch.
•3: Rumbling, bulging forces, subsonic rumbling.
•4: Caster hovers up to 5’ off the ground.
•5+: Creatures within 30’ take 1 damage per round.
The caster may add other minor illusions as desired. 
"What is that wizard doing?" is a very good distraction tactic. The 1 damage aura isn't too powerful, as it takes many rounds to get it online, but it's a direct damage in a class that doesn't have many options for direct damage.
7. Darkvision
Illusionist 2, Magic-User 2   
R: touch T: creature D: 1 hour
Target can see up to 60’ in darkness.
1 hour of darkvision is useful but not game-breaking.
8. Deprive Sense*
Illusionist 2   
R: 30’ T: creature D: permanent
Target must Save or lose one sense (sight, hearing, touch, taste, smell) of the caster’s choice.
Reversed: Cures magically one magically imposed lost sense.
If I'm going to combine blindness/deafness into one spell, I might as well have all of them. Yank someone's sense of taste and then poison them. Remove an ally's sense of smell so they can invade the lair of the Dire Carrion Crawler.
9. Detect Magic
Cleric 1, Druid 1, Illusionist 2, Magic-User 1   
R: 30’ radius T: self D: 10 minutes
Magical objects glow. The caster may test Intelligence to obtain vague hints about the type and strength of magic, at the GM’s discretion.
Another infrastructure spell.
10. Escapology
Illusionist 2   
R: 0 T: self D: 0
The caster escapes from any bonds, shackles, or impediments. Any effects that negatively affect the caster’s movement speed (e.g. the slow spell) end. This spell can be cast silently and with minimal hand motions.
Stage magic. The category of "any impediments" is deliberately broad, but with a duration of 0, this can't help the caster navigate a tangle of thorns or a corridor filled with webs. It helps once, then it's done.
11. Feign Death*
Druid 2, Illusionist 2, Magic-User 3   
R: touch T: creature D: 1 hour
Target willing creature appears to be dead. It cannot see or move, but can hear. It reduces all incoming non-magical damage by half. The effects of diseases or poisons are paused until the spell ends.
Reversed: Target human-sized corpse appears to be alive, but in a deep magical slumber.
A 5E import, but it's a useful tool. The damage resistance is surprisingly handy if, for example, you want to use a hireling as a bobsled.
12. Hypnotic Pattern
Illusionist 2
R: 15’ radius / unlimited T: self D: concentration
Swirling colours and shapes fill a 15’ radius around the caster. Creatures in the area that can see the pattern must Save or be hypnotized. Up to 24 total HD of creatures can be hypnotized. Affected creatures will stand and watch the pattern. The effect ends for a creature if it is harmed. The caster may not move while concentrating.
Another classic. Not much to say about it, though it should be noted that it affects all creatures, not just ones targeted by the caster. Catching allies with this spell is traditional.
13. Invisibility
Illusionist 2, Magic-User 2   
R: touch T: creature D: 1 hour
Target creature is invisible. The spell ends when the target takes a hostile action. Clothing and carried items are also invisible.
It's hit after hit at level 2. 
14. Locate Object*
Cleric 3, Illusionist 2, Magic-User 2   
R: 120’ T: object D: 10 mins
The caster names an object or class of objects (e.g. stairs, swords, the Crown of Ipbid). If it is within range, they learn its vague location, direction,  and distance.
Reversed: Target touched object cannot be located by magical means for 24 hours.
The reversed version makes sense. It's low-level magical interference. It's rare that a campaign revolves around anti-scrying, but it's a useful tool.
15. Magic Mouth
Illusionist 2, Magic-User 2   
R: touch T: object D: permanent
A mouth appears on the object. It records a message of up to 25 words and will speak it when the conditions set by the caster are met. The conditions can be as complex as desired, but must occur within 30’ of the object, and must rely on external appearances or visible actions.
Another scheme-enabling spell. 
16. Mirror Object
Illusionist 2   
R: touch T: object D: [caster level] hours
The caster creates an illusionary copy of an object that fits in a 5’ cube. The copy is silent, slightly glassy, and is destroyed if it is dealt damage. It has the same weight and texture as the original, but has no magical properties or special abilities.
Is this your card? Your crown? Your plot-supporting artifact of baleful influence?
17. Phantasmal Force, Improved
Illusionist 2   
R: 240’ T: point D: concentration, up to 10 minutes
As phantasmal force, but the illusion is smaller than a 60’ cube, may create minor noises and odours, and has realistic texture. Saves to see through the illusion have a -2 penalty.
I'm not a huge fan of "this spell but better" progression, but improved phantasmal force is an interesting tradeoff for the class's workhorse spell. Yes, it's more realistic, but those 2nd-level spell lots are precious. The rearranged name keeps the spell next to phantasmal force in the book.
18. Silence
Cleric 2, Illusionist 2
R: 120’ T: creature or point D: 1 hour
Nothing can create sound in a 15’ radius. Spellcasting is impossible. If the spell targets a creature, the creature may Save to have the spell apply to their current location. If they fail, the effect moves with the creature.
Another spell with many uses. Ambush a guard without alerting anyone in the next room, stymie spellcasters, hack down a door in peace and quiet, etc.
19. Sleight of Hand
Illusionist 2   
R: touch T: object D: [caster level] hours
Touched object that fits in a 2’ cube vanishes up the caster’s sleeve or behind their back. If the object is held, the creature holding it may Save to negate. The item remains in an extradimensional space for the spell’s duration or until the caster retrieves it. If the caster is knocked unconscious, the item reappears. 
Hammerspace! Few people know that the term comes from The Saga of Ragnar Lodbrok and his Sons. "Kanín Hamar was the name of Önd the Wild's brother. He escaped from the battle with the standard of Eldmar the Bald, and his sword and shield, and his arm-ring weighing three marks of gold, and his wood-axe, and two of his sheep also." [citation needed] [citation will not be found]
20. Whispering Wind
Illusionist 2
R: [caster level] miles T: creature or point D: 6 hours
The caster whispers a message of up to 25 words, then names a creature known to the caster or known point within range. The message travels on a gentle breeze, where it is heard as a whisper. The caster may have the message arrive instantly or at any time within 6 hours, chosen when the spell is cast.
It's a low-level messaging spell. Pretty useful for coordinating schemes, but the target has to be able to hear a whisper.
Pavel Maksymenko

Level 3

1. Butterfly Hurricane
Illusionist 3   
R: 30’ radius T: area D: concentration
Creates a whirling, brightly coloured mass of butterflies. Blocks line of sight for all creatures except the caster. Ranged attacks that pass through the area automatically miss. Creatures other than the caster who end their turn inside the area must Save or be stunned for 1 round.
"I'm an illusionist and I'm a massive inconvenience to friend and foe alike."
2. Colour Bomb
Illusionist 3   
R: 240’ T: point D: 0
A shimmering bead flies from the caster’s hand. 10’ radius blast. Sighted creatures in the area must Save or be affected based on their HD:
•Under [caster level]: Unconscious for 2d8 rounds.
•Equal to [caster level]+2: Blinded for 1d4 rounds.
•[Caster level]+3 or more: Stunned for 1 round.
 An Aronson spell; colour spray with range.
3. Conceal Intent*
Illusionist 3   
R: touch T: person D: [caster level] hours
The target’s intentions and nature are concealed from spells such as detect evil (pg. ###). The target cannot be located by magical means.
Reversed: Target creature must Save or loudly announce their actions for [caster level] rounds. The target does not have to reveal future plans. 
Conceal alignment, detect thoughts, and baffle clerics. Trick reality.

4. Daydream
Illusionist 3    
R: 120’ T: spellcaster D: 24 hours
Target spellcaster must Save or fall into a pleasant daydream, taking no actions. The effect ends if the spellcaster takes damage.

This spell is derived from Aronson's updated Illusionist. It's a sort of low-level feeblemind. I'm not entirely sold on it, and it might be cut during revisions, but it's on the list.

5. Dispel Illusion
Illusionist 3
R: 120’ T: point D: 0
Any illusions within a 30’ cube are dispelled. Illusions partially within the spell’s area of effect are truncated or distorted. 
I like the idea of using a cube here rather than a radius effect because it neatly chops illusory scenes along a clear boundary, while capturing most large illusory creatures.
6. Fear*
Illusionist 3, Magic-User 4   
R: 60’ cone T: area D: 0
Creatures in the area must Save against fear or flee. Creatures that fail the Save have a 1-in-6 chance to drop held objects. Creatures flee for at least [caster level] rounds.
Reversed: Creatures affected by fear may make a new Save with a +2 bonus. If they pass, they stop fleeing and gain 2 temporary HP. 
Giving fear a reversed morale-boosting spell is a nice bonus. Dropping held objects is a great part of old-school fear effect; it's so handy for looting.

7. Flare•
Illusionist 3
R: 0 / 360’ T: point D: [caster level] rounds
A spluttering red flare flies from the caster’s finger. It travels 360’ in a straight line, bouncing off walls or obstacles until it has travelled the full distance, then floats in the air. The flare casts light as a torch. The caster may detonate it on any subsequent round within the spell’s duration. 20’ radius blast, 2d6 fire damage, Save for half, Save or be deafened for 1d4 rounds, fills the area with opaque smoke for 10 minutes.

Direct damage with a pretty serious accuracy issue. The dot () means the spell deals elemental damage, and that the element in question can be adjusted to create variant spells.

8. Glitterblast
Illusionist 3
R: 30’ cone T: area D: [caster level] days
Creatures and objects in the area are coated with a fine layer of sparkling dust. The dust fades over [caster level] days. Ethereal creatures are not affected, but invisible creatures effectively become visible. The dust persists even if a creature transforms or becomes invisible.
Mark shapeshifters, inconvenience nobles, fascinate goblins, and conceal treasure beneath a layer of glitter. This could be a lower-level spell, but I feel like it would see too much use if it was at level 2, especially with the long duration.
9. Hallucinatory Terrain
Druid 4, Illusionist 3, Magic-User 4   
R: 120’ T: area D: varies
The caster cloaks the area in an illusion. A swamp can be made to look like a meadow and vice-versa. The terrain can appear impassible or deceptively inviting. The area affected is a [caster level]x10’ square. The terrain lasts until it is dispelled or touched by an intelligent creature.
A versatile spell from OD&D wargaming roots. This spell is very handy for avoiding pursuit or concealing a secret path.
10. Hold Person
Cleric 2, Illusionist 3, Magic-User 3   
R: 120’ T: person D: [caster level] rounds
Up to 4 people must Save or be paralyzed for the spell’s duration.
A much weaker replacement of the Illusionist's traditional paralyze, but on the other hand, paralyze is a fundamentally boring spell.   
11. Invisibility, 10’ radius
Illusionist 3, Magic-User 3   
R: touch T: creature D: 1 hour
Target creature, and all creatures within 10’ when the spell is cast, are invisible. The area moves with the creature. The effect ends for a creature when the creature takes a hostile action or leaves the area. Clothing and carried items are also invisible.
Another standard spell in a compressed format.
12. Misdirect Scrying
Illusionist 3   
R: touch T: creature or object D: 24 hours
Target cannot be located by magical means. The caster may name another object, location, or creature that will be appear instead of the target.
There are a lot of scry-altering spells in the Illusionist list, making this one a candidate for elimination.
13. Mundanify
Illusionist 3
R: touch T: object D: 12 hours
Target object appears to be a dull, non-magical, worthless, or obviously forged copy of itself. Magic items do not detect as magical. The object’s properties are not affected. The object cannot be located by magical means. 
Useful for haggling, smuggling, and thievery. This might be rolled into a reversed magic aura (above) during revisions, but it might be too useful an effect for level 1.
14. Phantom Steed
Illusionist 3   
R: 30’ T: point D: [caster level] hours
A translucent illusionary steed appears. It can support one person and their equipment (chosen when the spell is cast), moves silently at 3x normal speed, and behaves as an obedient horse. It cannot be targeted, block damage, carry saddlebags or pull a vehicle. It gains abilities based on [caster level]:
•8+: Ignores difficult terrain.
•10+: Crosses water as if it were solid ground.
•12+: Ignores chasms and gaps, but cannot fly.
•14+: Can fly.
It's a horse that isn't a horse. Giving it the usual illusion '"destroyed if it takes damage" restriction would make the spell nearly useless for its intended purpose. Instead, the horse effectively doesn't exist.
15. Phantom Wind
Illusionist 3   
R: 360’ cone T: area D: concentration
A strong wind blows in the area. It does not affect and is not felt by creatures. Candles are extinguished, papers and loose objects flutter, and fog dissipates.
One of the strangest spells in the catalogue, but it's a proper wizardly effect. I'm not sure the wargaming-scale multi-ship abilities are useful to include; moving one ship as long as the caster concentrates seems useful enough for D&D purposes.
16. Space Swap
Illusionist 3
R: touch T: person D: [caster level]+2d6 minutes
The caster touches a willing person. At any time within the spell’s duration, at the start of a combat round, the caster may swap places with the target.
The Magic-User gets all the good teleportation effects, but I think the Illusionist should get one or two. It's a classic magic trick.
17. Splitting Image
Illusionist 3
R: 0 T: self D: [caster level] rounds
An illusionary duplicate of the caster appears. For every 3 [caster levels] past the first, they may create 1 additional duplicate, to a maximum of 3 duplicates. Duplicates sprints away from the caster, moving at maximum speed and making convincing screaming noises or meaningless babble. They can open light doors. Duplicates vanish if they take damage.
The mental image is hilarious. The caster should, ideally, turn invisible and/or sprint away at the same time, but it's not required. The effects only get more chaotic when combined with other illusion spells. The door-opening ability might be more useful than you'd think.
18. Suggestion
Illusionist 3, Magic-User 3   
R: 30’ T: creature D: [caster level] hours
The caster speaks a short, simple, and reasonable command to a target, which must Save or obey. The target must be able to hear and understand the caster. The command must be a plausible course of action. The verbal component of this spell is the suggestion, so a target that fails its Save may not be aware a spell was cast.
Another classic "turn one problem into a different problem" spell.
19. Unlight*
Illusionist 3   
R: touch T: object D: 1 hr+20 mins per [caster level]
Target object casts light as a torch. Only the caster and up to [caster level] creatures designated when the spell is cast can see the light.
Reversed: Target object casts darkness instead. This darkness does not the caster and up to [caster level] creatures designated when the spell is cast. It affects magical light.
I'm not a fan of continual light. If you want a permanent light source, use permanency on light spell, with all the associated time and effort costs, or get a magic item. The light economy is important. This is an illusionist-only better light spell.
20. Wraithform
Illusionist 3
R: 0 T: self D: [caster level] rounds
The caster becomes insubstantial and slightly translucent. They are immune to non-magic damage, cannot speak, cast spells, or take hostile actions, and move at ¼ speed. Clothing and carried items are also affected. Mindless undead ignore the caster. The caster can squeeze through small gaps, but it takes 1d4 rounds to slip under a door or through a keyhole.
I don't like gaseous form-type spells. They trivialize a huge number of challenges. Immunity to some traps and most damage, slipping under doors, investigating things secretly, arguing with the GM about turning into a solid when you're up a creature's nose. It doesn't encourage cunning plans. If you want to turn into fog, become a vampire like a sensible PC. On the other hand, the illusionist does need something at level 3 that compensates for missing all the goodies on the magic-user list. Turning into a slow-moving ghost might be enough.

Final Notes

Hopefully this post reveals some of the process behind the Treasure Overhaul. Spells are tricky. Spell lists are trickier, especially when you're starting from a canonical list and working for broad compatibility. If you have strong feelings about any of the changes I've made, post in the comments and I'll see what I can do.