Alternative Magic Systems

[Halaster]

Various threads on how the D&D magic system is unbalanced or problematic lead me to consider how other rules systems handle magic and how such mechanisms might be adapted to D20 rules. I'd like everyone to contribute by adding what systems they know or can think of. Below I've gathered a few approaches I've come across and how I imagine they could be adapted to D&D. Of course, many of these will make the class distinctions already in place useless and nullify class abilities all over the place. Still, they might make a good choice for a custom class which fits more snugly into the tiers where non-casters can be found.

Finally, before reading on note that I'm really only familiar with core. Maybe many of these options have been explored by variant classes. If so, please point me to them.

Pay per spell

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Mechanism: Caster has spell points. Each spell costs points. Points are deducted after caster. When points run out, no casting anymore. Points recover over time.
Used by: Rolemaster
In D20: already exists: Pisonics. Adapting other classes to match seems pointless.

Roll to cast

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Mechanism: Caster has no spell points or spells per day. To cast a spell, he makes a success roll. If roll succeeds, spell is cast. No limit to casting.
Used by: Hârnmaster, Hero Wars
In D20: Spellcraft or caster level rolls might work. Could turn into a balancing nightmare: casters are either useless (very high difficulties) or overpowered (lower difficulties). A non-linear progression might work, making low-level spells ubiquitous and high-level ones epic.

Roll and pay

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Mechanism: A combination of the above
Used by: GURPS
In D20: see above.

Ambient energy

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Mechanism: Caster has no spells per day or spell points. Caster spends actions to gather ambient magic into his spell. Once sufficient energy has been gathered, spell goes off. Magic may run out locally, but if caster moves, magic may become available again.
Used by: Castle Falkenstein, Pendragon, Magic: the Gathering
In D20: A standard action yields one level worth of energy. Magic-rich or special areas (consecrated temples/groves, ley lines, etc.) might yield two or three. Pearls of power and similar items store levels, usable once per day. Areas can be rated in levels/day of ambient energy. Makes low-level magic ubiquitous and high levels rare.

Spell Matrix

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Mechanism: Caster has no spells per day or spell points. Instead, he has spell matrixes (matrices? matrixi?), which he can load with spells. He can then cast these spells at will (perhaps with a roll).
Used by: Earthdawn (with a wiff of Ambient Energy)
D20: Each caster has 1 spell matrix per 3 caster levels. He can spend 10 minutes (per level? 1 minute per level?) to load it with a spell that can then be cast as a standard action, as often as he likes. Might make low-level spells too much of a waste of matrixes. Could be combined with ambient energy in a limited form (1 standard action/x spell levels to prepare)

[Lapak]

'Roll to cast' has been done - poorly - by the Truenamer, from the Tome of Magic. It uses scaling DCs based on enemy HD, how often you've used your effects, and many other things. The official presentation did not work well, but people on the Homebrew forum have put together a few fixes.

In terms of a style that you didn't list but has been done officially, the Incarnum system (from Magic of Incarnum) functions as a 'Static Effects Chosen at Start of Day' system. Incarnum users choose what 'melds' they will set up at the beginning of the day, giving them an array of magic powers, and can then boost one meld or another by shifting their power-pool around during the day.

EDIT: Let me clean that last up a bit.

Variable Static Effects
Mechanism: Caster chooses various effects from a list at the start of each day. Effects can be boosted by a power pool; these boosts can be moved about during the day.
Used by: Magic of Incarnum
In D20: As above.

[Count D20]

The d20 srd has a spell-point adaptation for the basic classes.
It looks pretty good.
If you want a way for casters to regain power without an eight hour rest , it makes it easier. You could add magic potions, rests or whatever.

[Draz74]

Self-Damage
Mechanism: Caster damages self when a spell is cast.
Used by: Many systems, including, in a way, Risus.
In d20: Before you even think about implementing this, you have to make hit point healing harder to come by. And worry about infinite loops of Clerics who use this. Sucks for gishes, too.

Casting Fatigue
Mechanism: The spellcaster has to roll when he casts. The spell works, either way; but if the roll fails, the spellcaster is left one step lower on a condition track that leads to being too tired to cast anymore.
Used by: True20
In d20: much like the above, you have to worry about how easy it is to be cured of Fatigue in D&D via magic, e.g. Lesser Restoration spells. If you get that issue straightened out, though, I think this could actually work.

Non-Renewable Pay Per Spell
Mechanism: Like Pay Per Spell, only the resource you're paying with isn't something innate to your character that comes back when you rest. Instead, you're paying with a meaningful amount of in-character money; or permanently aging your character, bringing her one step closer to inevitable death by old age; or things like that.
Used by: Many. Presumably the Mistborn RPG, if it ever comes out. I forget which popular game uses the aging mechanic as its major balancing factor. Ars Magica, maybe?
In d20: I guess this is used a little bit, with component costs (especially for 4e Rituals). 2e and earlier even had the aging thing for certain spells. But these things could be drastically expanded. Doing so seems to be against the mainstream "feel" that D&D magic reaches for, though.

Impractical Casting Times
Mechanism: You can do magic as often as you like ... but it's not too powerful in combat, because a warrior can easily hack you to pieces while you're casting even one spell.
Used by: dunno.
In d20: Rituals and Incantations hint at this. D&D seems to want to avoid making this true of all magic, as combat spellcasting is something of a classic of the sub-genre. But I, for one, can never figure out why at least some spells don't use this more. In 3e, Teleport would cause so many fewer campaign-breaking problems if it required 10 minutes of casting, but instead it's merely a standard action ... Why?

[arguskos]

I feel it's worth mentioning Recharge Magic, which is not quite the same as the ambient energy suggestion above. Gogo d20srd!

[ShneekeyTheLost]

The Invocation system is about as balanced a magic system as I've seen.

Basically, you can 'badda bing, badda boom' an unlimited number of times, but you really don't have any reality-shattering effects at your beck and call.

Throw in 'rituals' which take a minimum of 10 minutes (ala 4e) to produce some of the more powerful static effects (Identify springs to mind), and you're gold.

Impractical Casting Times was used by GURPS. Spells that do more damage take up more time to cast. If you wanted a 3d6 Fireball (which is quite a lethal thing), you take 3 turns of Concentrate before you can launch it. At a single target. By which time, the fight is either over, or you are quite dead. Unfortunately, there were too many loopholes to avoid this problem, so it didn't work out as Steve Jackson intended.

[Dirty n Evil]

I'd be remiss if I didn't mention the Mutants and Masterminds system. From what I understand, there are quite a few people out there that have already abandoned their 3.5 / Pathfinder / 4th edition system except purely for inspirational and reference material and just run everything through M&M. As a system where you build everything from the ground up, you can have your spellcaster character know exactly the sort of spells you want them to with the particular bells and whistles you want it to have. Me and my friends find the M&M system a bit time consuming for builds, though, but perhaps when we get a better sense of its ins and outs we might attempt a fantasy M&M game.

But for the record, I've never liked the D&D spell system. It's too rigid. For example, I'm currently running a tiefling wizard named Rory, and I like the idea that Rory has a theme to his combat spells... namely, cold. (He's from a colder climate.) But in order to have his damaging spells work that way, he's required to take the feat "Energy Substitution" - rather than say, just switch out the energy discriptor permanently for him in how he has it written in his spellbook. But that's the way the spell is written, so he has to sacrifice one of his very costly wizard feats just for that effect. Bleh.

[Aotrs Commander]

I've played around with using a mana-points system (as opposed to spell points *shudder* or psionic's rather better system). My own findings are that one of the major issues is spell access; i.e. how many different spells you can cast seems to be more problematic for D&D than the number of spells (.e times per day). And, of course, also the easily-abusable or outright broken individual spells themselves.

Most, if not all of the mentioned systems will have the same issues caused by making everyone "spontaneous" casters. I think a better starting point for alternate magic is looking at a way to restrict the spell lists of the major offenders who often have effectively unlimited spell lists (all the Tier 1s, for example). I think if you can find a way to restrict or reduce that access to the "unlimited" spell lists (and deal with some of the offending spells), the actual system of casting them doesn't matter that much.

[JoshuaZ]

Non-Renewable Pay Per Spell
Mechanism: Like Pay Per Spell, only the resource you're paying with isn't something innate to your character that comes back when you rest. Instead, you're paying with a meaningful amount of in-character money; or permanently aging your character, bringing her one step closer to inevitable death by old age; or things like that.
Used by: Many. Presumably the Mistborn RPG, if it ever comes out. I forget which popular game uses the aging mechanic as its major balancing factor. Ars Magica, maybe?
In d20: I guess this is used a little bit, with component costs (especially for 4e Rituals). 2e and earlier even had the aging thing for certain spells. But these things could be drastically expanded. Doing so seems to be against the mainstream "feel" that D&D magic reaches for, though.

Well also xp costs are sort of life this. I've seen people try to make completely xp based casting systems for d20 and have yet to see one that was reasonably balanced. It is quite hard to do. Regarding Mistborn, I'm not sure what you are talking about. Do you mean the feruchemy? That only requires storing up traits, you still have the total amount at the end.

[Draz74]

Regarding Mistborn, I'm not sure what you are talking about. Do you mean the feruchemy? That only requires storing up traits, you still have the total amount at the end.

I haven't seen any of the RPG's actual rules, so this is pure speculation. But it seems like the main "cost" that keeps Feruchemy in check is the amount of down time required to store up magic, and the main "cost" to using Allomancy is the monetary cost of the metals you had to buy and eat. So both are limited in a way that's pretty different from traditional RPG magic limitations.

[Edge of Dreams]

Another option is what the Dresden Files RPG (and some others do too, I think). Magic is a generic thing, rather than having set spells. Players choose how much 'power' they want to put into a spell, which sets the DC for the roll to control the spell and not have it blow up in your face. Actual effects of the spell can be flavored any way you want, but mechanically they always fall into one of a few basic types: Attack, Block, Counter-spell, and Manuever (which have specific meanings in the combat system of this game). There is a simple system for determining how power translates to effects. For example, power translates to damage on a 1-to-1 basis, and a certain number of points of power can be traded in to make the spell AOE instead of single target.

[Tyrrell]

Draz74 Ars Magica is closer to casting fatigue than any of the other choices you've got up there but it significantly more rich and descriptive than what you see in other systems some some way or another you can get any of te relations you included in your post.

One method that hasn't been mentioned yet is roll to avoid magic biting you in the rear. This is the system in Dark heresy/Rouge rader/Deathwatch and more famously Mage the Ascension. Magic will eventually screw you over hard every time you stretch yourself there's a chance that the universe is do its magic on you in a less than fun way. (There is a bit of this in Rolemaster and Ars Magica as well)

[Draz74]

Draz74 Ars Magica is closer to casting fatigue than any of the other choices you've got up there but it significantly more rich and descriptive than what you see in other systems some some way or another you can get any of te relations you included in your post.

OK, cool, then the Aging-based magic I was thinking of must have been a different system. Wish I could remember which one.

[Xefas]

Exalted has the Pay Per Spell, mixed with Impractical Casting Times, and the occasional Roll to Cast.

The Pay Per Spell comes in the form of Motes (which everyone has, but spellcasters use them for spells).

Impractical Casting Times comes in the number of actions that it takes to cast being equal to the Circle of the spell (1st, 2nd, or 3rd). So, casting a 1st Circle spell is kind difficult in combat, but if you time it right, you can get one off without getting owned, assuming you aren't fighting a wicked-fast opponent, in which case there's no way to time it right.

2nd and 3rd circle spells, forget it. If you cast one in battle, there's a high enough chance that you'll just get owned and lose your spell and mote investment that it doesn't really happen. The higher spells are more for before/after battle, long duration spells, or transportation (Or Magma Kraken-ing that army advancing on your left over there that you missed because you didn't put any points in Awareness).

Roll to Cast just comes in the form of, in my opinion, the most useful series of spells, the 'Summon X Circle Demon'. Most casters, that I've seen, go for these immediately upon reaching a new tier of spells, and for good reason. The catch, of course, being that if you fail your opposed roll, the demon is set loose to murder you in horrible ways, which it has a very high likeliness of doing (as you'll be out of motes from summoning it).

It's not my favorite system of casting, but it's probably #2ish. Definitely fits the setting, at least so far as Solars go, in my opinion.

[Tyrrell]

OK, cool, then the Aging-based magic I was thinking of must have been a different system. Wish I could remember which one.

I'd bet it was riddle of steel

[Halaster]

I like the Casting Fatigue idea. You could do that in D20 with energy drain: every time a spellcaster casts a spell, he or she incurs a negative level. Since most pure casters have more spell levels than character levels that would limit the amount of spells per day, while also making casters careful about slinging powerful spells, as it weakens them so much. Would of course encourage multiclassing, which might not be a bad thing.

Alterrnately, you could take a page from the Lord of the Rings RPG and have the caster make a save (Will or Fortitude) against the spells DC on casting. If he fails, he's fatigued for 10 minutes or 1 minute per spell level. Might help lower casting frequency.

[UserClone]

Non-Renewable Pay Per Spell
Mechanism: Like Pay Per Spell, only the resource you're paying with isn't something innate to your character that comes back when you rest. Instead, you're paying with a meaningful amount of in-character money; or permanently aging your character, bringing her one step closer to inevitable death by old age; or things like that.
Used by: Many. Presumably the Mistborn RPG, if it ever comes out. I forget which popular game uses the aging mechanic as its major balancing factor. Ars Magica, maybe?
In d20: I guess this is used a little bit, with component costs (especially for 4e Rituals). 2e and earlier even had the aging thing for certain spells. But these things could be drastically expanded. Doing so seems to be against the mainstream "feel" that D&D magic reaches for, though.

http://www.giantitp.com/forums/showthread.php?p=2487790

[Greenish]

Alterrnately, you could take a page from the Lord of the Rings RPG and have the caster make a save (Will or Fortitude) against the spells DC on casting. If he fails, he's fatigued for 10 minutes or 1 minute per spell level. Might help lower casting frequency.

Well, it's not like Fatigue does much to hinder a caster.

[UserClone]

Unless you make it so that casting while fatigued renders you exhausted and unable to cast spells until you rest for an hour, after which you become merely fatigued.

Just like the class in the link I posted above.

[Frozen_Feet]

LotR RPG, using the CODA system, has roll to cast with fatigue. Fail a stamina roll, and you both lose the spell and become more fatigued. Casting in rapid succession also increases the difficulty of the stamina roll. As fatigue gives penalties to all rolls (up to -9 on a system that uses 2d6 rolls), it also makes further castings more difficult. This prevents casters from spamming their spells and forces them to rely on ordinary skills - which is fine, because there aren't many spells you'd want to spam anyway.

This would be reasonably easy to adapt into D&D, but would require redefining Fatigue and assigning a Fortitude DC to all spells.