Materia-esque System For Old-School D&D-style RPGs

QUICK SUMMARY:

• This system envisions materia as magic gems that can either be attached to a person’s body to be used as a wand, or attached to equipment to grant it an effect (the choices are mutually exclusive).
• GM picks one of these materia to insert into the game or a treasure table as a magic item.
• GM picks 2 or so spells from the list for that materia and decides the materia’s die size (usually d6).
• Casting spells costs a number of rolls which ticks the usage dice down (roll the d6, if you get a 1 or a 2 it becomes a d4, then on further rolls if the d4 gives you a 1 or a 2 the materia becomes inert).

This is my attempt at replicating something like materia from Final Fantasy VII. In practice, it’s going to feel more like an homage to magic systems from a few different games from that era — runes from Suikoden and rods from Final Fantasy V definitely have just as much influence.

The general idea here is that you take these little magic gems and place them as treasure in your world where you might normally place scrolls or similar magic items. Characters can then attach the gems to their body or equipment to enhance their abilities. You could theoretically strip Magic Users from your game and attach all of those spells to these gems instead. However, I’ve intentionally designed it to be a little weaker and more limited than the effects of regular B/X-style Vancian magic. Thus, if you do decide to keep Magic Users in your campaign, there’s still a point to picking them. And if you don’t, these will still feel powerful without throwing much of a wrench in the math.

This is calibrated to old-school D&D. In old-school D&D, spells tend to do about d6 per level damage, and less than that for an AOE spell or if they offer some other benefit. These spells roughly follow that assumption. You can use materia with D&D 5e, but consider stepping all the dice up a size for the spell effects if you do.

Basic Mechanics

• Characters can equip up to three materia; one of to each of three places: 1) somewhere on their body, 2) their weapon, and 3) their armor or shield. Once attached, it takes about an hour for the materia to become active and usable.
• When a character uses a materia they have attached to their body, they can cast any of its associated spells. Attaching materia to weapons does not allow you to cast spells, but instead grants access to some kind of elemental damage or status effect, while attaching it to armor helps protect a character from a particular effect. Because elemental resistances are a big thing to have in D&D, I generally have avoided using those as weapon or armor abilities, and instead feature them as spells.
• Materia have “usage dice.”¹ As a cost for casting spells, you roll the materia’s usage die as many times as told to, and switch to a lower die size when you roll a 1 or a 2. So if you use a d6 materia and roll a 1, it becomes a d4 materia. Each spell in a materia description tells you how often to roll the die. The average materia usage die is a d6. Some spells have variable costs based on the effects chosen. You must choose these effects and successfully complete all rolls of the usage die before the spell may be cast.
• When you roll a 1 or a 2 to use a d4 materia, it becomes inert after casting the spell. It needs a full day of non-usage to work again, at which point it becomes a d4. If its max is higher than that, it will step up a die size every day of non-usage thereafter. If a materia’s usage dice is reduced to 0 before you are done paying the cost of the spell you chose, you make a choice: shatter the materia to finish casting the spell or simply have the spell fail. Inert materia do nothing in armor or weapons.
• In my example materia below, there are more spells listed than you should realistically be putting in the materia you use in your game. Start each materia with its weapon/armor abilities and two spells. Reserve Shatter abilities for materia of a d6 usage die or higher.
• While most materia follow the common format of casting spells or doing something cool to your weapon or armor, you can also always attach whatever magic item effects you want to one. For example, you could have materia that summons monsters or which grants a skill bonus. I’ll provide a couple examples of these as well.
• Optional rule: Characters of level 4 or higher can choose to transform into materia on death. If they do, let the player choose a materia or design one on their own.
• Optional rule: If you’re interested in giving a bit of trade-off to using materia, try this: every materia equipped imposes a penalty which can be unique (and maybe thematic) to the materia. I would suggest something like 2 less max HP per materia, -1 ATK, or -2 stat points from STR or DEX, depending on your system. If you’re playing a game without magic users and want materia to feel like a full on bonus with no downside (like finding any other magic item), foregoing the penalty makes sense.

Finding Materia in the World

Locations: Materia occurs naturally in the environment. While a magic-using villain is likely to have some materia slotted, you’re also probably going to find them in deep, foreboding places generally untread by humans. Areas high in the magical energy that eventually forms materia give off a noxious miasma, so your players may need special protections to adventure in these areas. They’re also likely to interact with magically-mutated monsters.

Rarity: Materia should readily available, but valuable and expensive. They occur roughly as often as wands or scrolls. You could pretty safely combine them with those entries in the B/X treasure tables. This means that roughly 25% of magical items found will be materia. The majority of materia found are going to be a d4 or a d6 materia with just a couple spells. A d8 materia with four spells included would be an amazing find and probably a storied relic akin to a Holy Avenger; a d6 materia with two spells might be more like finding a Wand of Fireballs, and a d4 materia with one or two spells is more like finding a particularly useful scroll.

Upgrading: As most materia are not going to provide many options, I would recommend letting players spend money to upgrade materia and unlock more spells. This should cost roughly the amount it would to have someone in the world craft a magic weapon: costly enough that it shouldn’t be automatic decision, but not nearly on the level of building a keep. Requiring players to “sacrifice” other materia to create a new one is a good way to keep a lid on the power level. When players do upgrade their materia, the number of spells is going to be the main things you adjust when making rarer materia. Increasing the usage die is often a huge power jump akin to changing the rarity of an item, so keep that in mind. Players will suddenly be able to cast 2 Roll spells all day with minimal resource expenditure, which is a thing you might not happening at the beginning of the campaign.

The Standard Materia Template

Attack spell – 1 Roll. Ranged attack for d6 x level damage or d4 x level damage + effect.
Stronger Attack Spell – 2 Rolls. AOE/line effect attack for d6 x level damage or d4 x level damage + effect.
Room-affecting spell or utility – 1 Roll. This spell usually shouldn’t do damage. Environmental effects are better for this than things that directly affect a creature. These spells shouldn’t solve whole dungeon rooms but rather create interesting play when combined with other tactics. Aim less for Sleep, Invisibility or Fly and more Grease, Phantasmal Force or Tenser’s Floating Disc. Another good rule of thumb is that if it simulates something that would be 3rd level or higher in D&D, step the usage die cost up to 2 rolls.
Defensive or Offensive buffs – 1 Roll. These are most interesting when you need to use them on another creature, but it works fine either way.
Save or Die effect – 2 Rolls, and it should usually target just one creature. If it targets more, it should go up to 3 or more rolls.
Weapon Ability – Add an element. However, not all elemental properties have practical utility. When the benefit of adding an elemental affinity to a person’s damage seems low or unlikely to come up, instead have an effect activate when you roll max damage with that weapon.
Armor Ability – Provide protection against the opposite element or some ability affecting the character’s body. It’s ok for these to be strong (e.g. Ice materia flat out gives fire resistance). Player characters on defense in an OSR system are at a disadvantage anyway, so strong abilities here won’t translate to making it an obvious choice to slot materia into armor.
Shatter Ability – Very powerful problem-solving utility OR large AOE and good damage OR some combination of two weaker effects. These have parity with MU spells somewhere between 3rd and 5th level spells. Using these will shatter the materia. If you intend to run games beyond levels 1-5, consider buffing these abilities.

Example Materia

FIRE
Kindle (cantrip)- 0 Rolls. Touch a flammable object to warm it. If you hold it a bit longer, you can light it on fire as though you were using a torch.
Flamethrower – 1 Roll. 5′ x 30′ Line effect (Save dex/breath) for d3 +1 x level and burns any wooden objects in its path.
Fira – 2 Rolls. Creatures in 10′ radius sphere must save dex/breath or take d6 x caster level damage (half on success).
Immolate – 1 Roll. Set yourself on fire. You take d6 damage every round you endure this flame. At any time on a subsequent round, you can explode, dealing d6 damage per round you endured the flame to all creatures in a 10’x10′ radius. Creatures can save dex/breath to take half.
Heat Wave – 1 Roll. The temperature of the room or surrounding area reaches about 40 degrees Celsius. It becomes unbearable to wear armor in this heat. Creatures wearing it or similarly warm clothing will need to roll morale to do anything too athletic and will generally try to seek cooler temperatures.
Control Flames – 1 Roll. If a fire is going in the area, you can use this spell to extinguish it or spread it to any other flammable object from a distance. For 2 rolls, this spell can be used as a response to another fire spell to nullify it.
Fire Sheath – 1 Roll. Grant fire elemental damage to a weapon and step its damage up a die size. If a weapon does 2d6 damage, the next die size can be 3d6.
Cauterize – 1 Roll. Choose a creature with 5 or less HP who is not at full health. You apply heat to their wound and they heal d4 HP.
Weapon Ability – Treat the weapon’s damage as fire damage. The weapon can act as a torch when unsheathed, including the ability to set fire to objects with enough exposure.
Armor Ability – You take half damage from cold spells. When you roll to save against cold effects, roll twice and take the better result. You can move about comfortably in extreme cold.
Shatter Ability – Firaga. Creatures in 20′ radius must save dex/breath or take d6 x caster level damage (half on success). Wooden objects are incinerated, and iron and steel objects begin to melt.

ICE
Frost (cantrip) – 0 Rolls. Chill a single object no bigger than the size of a person to as low as 0 degrees C.
Frost Armor – 1 Roll. Grant heat resistance to another creature.
Ice Shards – 1 Roll. Ranged attack for d4 x level. Opponent then makes a Strength/Stone save and on failure is slowed for a round (BX example – auto-loses next initiative).
Ice Slide – 1 Roll. Turn a wet surface 5 ft wide and up to 60 feet long into slick ice. Creatures trying to maneuver while standing on this must save or fall prone. If they fall prone, they additionally slide toward the end of the slide unless something stops them. Creatures trying to cross this slide must treat it as you would difficult terrain if they don’t want to make the save.
Melt – 1 Roll. Become part of snow for up to 10 seconds. At the end, you may reappear as normal in any area covered in snow, as long as there is a contiguous line of snow leading there from where you started.
Blizzard – 1 Roll. Torrent of snow fills the room. If outside, localized flurry occurs. Temperature of the room drops to 0 degrees C.
Freeze – 2 Rolls. Enemy must save against strength/stone or become frozen in place. They must spend their next action to break free, and they become slowed the turn after.
Ice Beam – 2 Rolls. d4 x level damage and works as a 5′ x 30′ line effect.
Weapon Ability: On max damage roll, enemy is slowed for a round.
Armor Ability: You take half damage from all fire or heat-based attacks. You can move about comfortably in extreme heat, including walking through fire. Nothing you wear or carry can catch on fire.
Shatter Ability – Blizzaga. As Blizzard, but all creatures without some form of cold resistance or not taking shelter additionally take d4 x level damage and must save (Str/Stone) or are slowed.

LIGHTNING
Conduit (cantrip) – 0 Rolls. After you cast this spell, you can act as a conduit for electricity without incurring harm for as long as you concentrate (without performing any strenuous actions). Electricity from any source, including another spell, can flow from you to any electrical conductor you touch. If you are not touching another conductor, you must touch one to discharge the electricity within 10 seconds or take appropriate damage. If you choose, you can spend 1 Roll to discharge the electricity as a ranged attack or 2 Rolls to cast this spell in response to imminent lightning damage.
Electrify – 1 Roll. You can imbue any electric mechanical device about as big as a car with sufficient electric charge to keep it going for a minute. If you expend a second Roll, you can keep it going for an hour. If you attempt to use this on a creature, follow the rules for Shocking Coat and the attack is disadvantaged.
Shocking Coat – 1 Roll. You sheathe your body in electricity for a round. On a subsequent round, you can choose to transfer it to another creature you can reach immediately as a melee attack for d4 x level damage. Alternatively, you can wait for an enemy to attack you. If they do, they take d4 x level damage with no save. If their attack would be successful, it does only half damage. The electricity disappears after using either effect.
Current – 1 Roll. Choose any continuous length of conductive material. You turn into electricity and instantly move up to 60′ along the surface of that material. If used in a thunderstorm or in rain, treat it as a 60′ teleport in any direction.
Storm – 1 Roll. Only usable outside. Summon a thunderstorm. Torrential rain falls from the sky and lightning bolts occasionally touch down. Characters wearing metal armor or holding metal weapons have a 10% chance each round of being struck for 2d6 damage. The storm clears up after about 10 minutes.
Thunder – 2 Rolls. Choose up to six creatures. They each must save DEX/Breath or be struck with lightning for level x d4 damage. The lightning comes from the sky if you’re outside, or from your body if indoors. If used in a thunderstorm, this only costs 1 Roll to use.
Flash – 3 Rolls. All creatures in front of you must save Will/Death or become stunned and blinded for a round.
Weapon Ability: On max damage roll, enemy is shocked and drops anything held in their hands if holding them. The objects fall a good 5 ft. or so away.
Armor Ability: You have a light coat of electrical energy around you. You take half damage from electricity. Additionally, when an enemy rolls minimum damage to hit you, they are shocked by the electricity and immediately drop their held items.
Shatter Ability – Thundaga. As Thunder, but you choose as many creatures as you can see and the creatures take d6 damage instead. You also immediately summon a thunderstorm (if you’re indoors, it happens outside and on the surface near where you are) as though you cast Storm. The storm lasts an hour and extends to the size of the hex you occupy or a 10 mile radius, whichever is smaller. It probably doesn’t need to be said, but do not check for lightning strikes from the storm for creatures not in the immediate vicinity of the caster.

LIFE
Feel Life (cantrip) – 0 Rolls. When you cast this spell, your spirit briefly touches that of complex life (e.g. animals or sapient beings) within 100′ feet of you. You know the general direction to all of them and how many hit dice they each have. The life forms you touch gain the same information about you, though they will not know why they received this information and will treat it as their own intuition.
Cure – 1 Roll. You heal a creature for 1d6 HP. You can Roll additional times, recovering +1d6 HP for each Roll you spend on top of the first.
Regen – 1 Roll. A creature you choose begins regaining 1 hit point every ten seconds for the next minute. If you spend two Rolls, this changes to 2 hit points. If you spend 4 Rolls, the creature regenerates a lost limb or organ instead of healing hit points.
Positivity- 1 Roll. You force a single undead creature of 3 HD or less to test morale. Its morale is treated as 7 for this purpose. If you ‘re not using morale, they instead have a 50% chance of fleeing.
Libra – 1 Roll. You scan the electric signature of a living creature. You learn all of its numerical stats and any weaknesses or resistances it may have. You also learn how many spell slots or other innate resource it has remaining.
Life Siphon – 2 Rolls. When used against an undead such as a Wraith, this ability does two things: 1) you make a ranged attack of pure concentrated light for 2d6 damage, and 2) if the hit is successful, you undo the effects of Energy Drain.
Reraise – 3 Rolls. A creature you choose is infused with a protective light. The next time within 1 dungeon turn that they fall to 0 HP, they immediately heal 1d6 HP and get back up.
Curaga – 3 Rolls. Up to 10 creatures you can see heal 1d4 HP.
Weapon Ability: Damage dice rolled for this weapon explode when used to attack undead creatures (explode means you roll the die again and add the new result to the previous result; the dice may explode multiple times).
Armor Ability: When an attack would take you to 0 HP, it instead takes you to 1 HP. This materia immediately becomes inert after this ability activates.
Shatter Ability – Raise. Acts the way a “Raise Dead” spell does in your game, minus any component costs.

CLEAR/MYSTIFY
Clear (Cantrip) – 0 Rolls. You can spend 10 seconds or a round clearing dirt, grime, dust, rust, etc. from a small space about the size of a book. Crevices and indentations are all cleared. The object or space looks the way it would have had it been carefully preserved by whoever abandoned it to ruin.
Fog – 1 Roll. Water vapor fills a room or 50′ radius (whichever is smaller), gradually getting thicker and thicker as time passes. It starts as a noticeable but not obstructive mist that permeates the room, and becomes more obstructive every round. By the time a dungeon turn has passed, it is nearly impossible to see anything within the room, though you can see the silhouette of anyone within melee range. If you spend 2 Rolls, you can produce the obstructive fog immediately.
Esuna – 1 Roll. You cure a creature of either a mundane poison, or of any affliction that lasts for an hour or less.
Muddle – 1 Roll. All spells cast — including your own — within a 30′ radius centered on you that involve auto-targeting (e.g. Magic Missile) or summoning lose track of their targets. The targets are randomly chosen among all creatures in the area instead, and summoned or created entities randomly choose their controller every round.
Dispel – 2 Rolls. End an ongoing magical effect originating from a spell, a wand or any similar implement that actively produces a magic effect when commanded to.
Sleep – 2 Rolls. All creatures you choose in a room or 30′ radius (whichever is smaller) remember how tired they are. They must test morale and seek their usual napping spot on a failure. They will jerk themselves awake if they become aware of any danger. If you spend 3 Rolls, creatures in this area instead must save against Death/Will or fall into a deep slumber on the spot for an hour.
Silence – 2 Rolls. Touch a spot within a room or a 50′ radius (whichever is smaller). No sounds escape their source in that room for an hour. Magic (including your own magic) that requires incantations is unusable. Sounds coming from sources outside of the area are still audible to people within the area.
Blink – 2 Rolls. Your shape becomes blurry and leaves after images, making you harder to hit. For the next ten minutes, whenever an effect other than an AOE targets you it hits an after-image instead. Your images have a d6 “usage die” like materia do, which means that when you are targeted you roll a d6 and lose a image on a 1 or 2, then switch to a d4. When you roll a 1 or a 2 on the d4, the last of the after-images go away entirely. If an enemy rolls maximum damage on their dice, they hit you instead of the after-images and you don’t roll.
Weapon Ability – A weapon slotted with this materia starts to look hazy and blurry, though it is still solid. When a creature is hit by this weapon, an on-going spell effect (be it positive or negative) on that creature ends, determined randomly.
Armor Ability – A character wearing this armor cannot be blinded, stunned, poisoned or put to sleep by spells or wands. They can still suffer these afflictions from other sources.
Shatter Ability – Innocence. For one hour, an area constituting a 1 mile radius or a dungeon (whichever is smaller) becomes permeated with an anti-magic effect. No spells can take effect in the area, and no spell effects can enter the area, including scrying. Magic-imbued items lose their abilities while in the area. No predictions of the future or readings of the past can account for what happens in this area during this time frame. Gods cannot view or otherwise interact with anything in this area, nor are they able to respond to those who try to contact them. Entities such as ghosts that exist for a supernatural reason other than a magic spell continue to exist.

GRAVITY (Might want to treat this as a particularly rare materia) 
Fall (Cantrip) – 0 Rolls. You point at any airborne object (e.g. arrows, bullets, rocks) and drop it to the ground immediately. Doing this doesn’t break a tether, such as a spiked ball attached to a chain or a chandelier attached to the ceiling; it just brings it to the lowest point the object and reach instead. You can also use this spell to halve the length and height of any character you can see attempting a jump. You can cast this spell any time in a combat round before you take an action, but you give up doing anything else in the round.
[Note: If you’re playing a game with Reactions as a resource, this ability shouldn’t rock the boat too much to cast just as a Reaction.]
Gravity – 1 Roll. 5′ radius forming a column reaching 1,000′ into the air. Intense gravity in the room for ten minutes. All movement rates halved, characters take two rounds to reach other characters if not tracking distance. Characters can not practically jump and no flight, even magical, is effective. All attacks in the area or which enter the area must be rolled twice, taking the worse result. All falling damage is doubled. Flyers who enter the area immediately fall to the ground and take falling damage.  If you spend 2 Rolls, you can expand this area up to to a 30′ radius (Gravira). For 3 rolls, it may be expanded up to a 100′ radius (Graviga). 
Reverse Gravity – 1 Roll. 5′ radius forming a column reaching 1,000′ into the air. An area you choose has lower than usual gravity for 10 minutes Characters spend half the movement to pass through this square and jump three times as high when in it. Climbing is extraordinarily easy. If you spend 2 Rolls, you can expand this area up to a 30′ radius. For 3 Rolls, it may be expanded up to a 100′ radius. 
Demi – 2 Rolls. A creature you choose takes and deals half damage, heals half the hit points they normally would, adds half (rounded down) the usual bonus to any roll they make, and counts as half the hit dice for any relevant effect. 
Weapon Ability – On max damage roll, reduce enemy HP to half of current HP. 
Armor Ability – You take no falling damage and you can jump and climb at double the rate. You may choose to ignore the effects of gravity manipulation, including any of effect of a gravity materia used against you.
Shatter Ability – Gravija. As Gravity, but the effect lasts 12 hours and has a 5 mile radius. At this scale, entire armies are likely to change route to avoid the affected area. Rations are consumed at double the rate per day if units spend any significant part of the day in the affected area. Sleeping in this area provides half the benefits and it is impossible to prepare daily resources such as  spells, maneuvers, etc. The table should agree on any further, less obvious effects this might have on a hex. Alternatively, as Reverse Gravity but the effect lasts 12 hours and as a 1 mile radius. Generally speaking, the benefits of this effect are the opposite of that described above. 

SHIVA (Summon Materia example, Very Rare)
Call – Renders the materia inert. A blue, magical humanoid creature who looks like this appears and helps you both this round and the next before departing (she acts last on each round). If she reaches 0 HP during either round, she leaves early. If playing B/X, treat her as as humanoid version of a Frost Salamander who can fly. Instead of the Frost Salamander’s 5 physical attacks, she can make 3 ranged attacks for 2d6 damage each. She has its other abilities, including the cold aura.
Weapon Ability – Grants your weapon +1d6 cold damage.
Armor Ability – Grants cold resistance. Makes you vulnerable to fire.
Shatter – You assume the form of Shiva for 24 hours.

COVER (Ability Materia example)
While this materia is equipped in any slot, you can choose to take a hit in place of any creature with 6 or less hit points remaining, even if they are at max HP. You teleport in front of them, take the hit, and then reappear where you were previously standing. This does not use your action for the turn.

¹ Stolen from The Black Hack.