Making Magic "Cost"

[VictorianMale]

In Kiero's thread (http://www.giantitp.com/forums/showthread.php?t=190106) about playing in a no magic game, panaikhan said:
I have played 'homebrew' D&D settings where magic cost the caster a lot more (one campaign, a caster had to make a Fortitude save (DR 10+spell level) every time. Fail, take spell level in damage. Save, take 1 damage).

What other ways have you seen to make magic "cost" the caster something?

[The Rose Dragon]

Play the Riddle of Steel, or Warhammer Fantasy Roleplaying. Those have such wonderful costs for using magic.

Alternately, I am partial to Pandemonium or Blue Rose (the latter of which has arcana and sorcery - sorcery is bad for you, but since most of the direct damage arcana are considered sorcery, and some of the arcana most effective on the world, it is incredibly tempting).

[Eldan]

I've seen various attempts to make systems like this, or to make magic unreliable...

The problem with many of them was that they were either so crippling that a mage would either blow themselves up twice per encounter or otherwise kill himself; or they could actually be resisted and negated entirely (ironically, sometimes with magic).

Damage is a common version, but, well, it can be worked around by gaining fast healing, regeneration or just healing magic.

Then there's just adding negative effects to magic. Magic ages you, or it drives you slowly mad. Systems with sanity systems (Cthulhu, or the variant in Unearthed Arcana) prefer that approach.

Magic could just cost money to use. Expensive material components. Of course, for this, you have to eliminate spells that create money, in some way.

Warhammer takes the Winds of Magic approach. You don't really now how strong the spell will be, and if it's too strong, the mage blows himself up.

[Mastikator]

In Trudvagn, you use vitner points (mana) to cast spells.
When casting you make a roll to see if you roll perfect, succeed, fail or critically fail.
On perfect roll the spell cost is halved, on success the spell functions normally.
On failure the spell fizzles and it costs only a minimal amount of vitner points.
On critical failure bad things can happen, ranging between "feeling bad" to "stroke", and in the middle it fails, but costs more than full vitner points.
And if you have 0 vitner points or less you instantly die.
You can take the equivalent of feats to make it more safe though, but it does mean that anyone but a master will risk death if they use it too often.

If it comes with a low- but significant risk attached then you can't use it as technology, but can still be used to overcome dangerous obstacles.

[hamlet]

I've always been a fan of the way it was handled in Ravenloft 2e (never looked at 3.x version). Essentially, fiddle-farting around with certain types of spells or other abilities (psionics and the like) drew the attention of the Powers and stood a non-negligible chance of landing you in a bad situation.

This kind of thing can easily be adapted to a broader scope, I think. Maybe any spell above a certain power level (say, 2nd or 3rd for argument's sake) stands a 5%/spell level chance of drawing the attention and ire of "something" out there that you'd rather avoid the notice of. Specific effects would largely be up to the DM. Might be something as simple as a random encounter with a monster, or as dramatic as being ported to an alternate plane/reality as punishment.

The 2ed Lankhmar setting book also had a system kinda like this, but a little silly in my eye. Essentially, every time a "black wizard" (aka a magic-user) leveled up, he'd have to roll on a table that gave him a random deformity. Looked like it would get rather silly rather quickly.

Complete Book of Necromancers also had dark gifts, which were beneficial, but came with a whole lot of hooks supposedly.

It all depends on how you want to play it. Is magic simply difficult (i.e., skill check to even pull a spell off?), inherently dangerous (i.e., hurts to do it), or dangerous in that it attracts attention or too much of it in one area tends to start unravelling things best left ravelled?

[Eldan]

I forgot: Binders.

3.5's resident Magic has a cost system, and a well-handled one, I think. You do not have much power of your own, instead you barter with entities from outside the cosmos for power every morning. Basically, you let them ride around in your soul for a while, so you can use their power. In exchange, they get to influence your actions to a certain degree.

[Jayabalard]

Learning spells can have a cost in and of themselves. I seem to remember this was a feature of the old TSR Conan RPG ( the one from the 80s), and I think I've seen in in a couple of other games. The idea is: even if you aren't making a pact with something, just learning the how te magic works can have a terrible consequence.
consequences on failure; lots of games have charts for this. Here's an example from the Powers and Perils (http://www.powersandperils.org/C_Abysmal.htm) site; it's a bit specific to that magic system, but there are some ideas in there you might be able to adapt.

[Kylarra]

Slayers D20 deals an amount of nonlethal damage to you each time you cast a spell. Since healing is restricted to an extent in the system, it makes for an interesting balancing mechanism.

[some guy]

I kinda like the idea of d20 CoC's style of casting. Besides Sanity damage you also take ability damage when you cast a spell. Wich ability is damaged and for how much depends on the spell, but what I like about it, is that magic can exhaust a caster.
When a spell damages your casting stat, it also adds an extra dilemma.

[Bagelz]

white wolf's Mage used paradox points, which built up over time.

It pretty much meant that a single use of magic had very little chance of bad side effect (unless it was very flashy or public), but continuous use had a very large chance of something bad happening.

dnd dark sun had defilers for arcane magic (which is why psionics were so prevailant), but i'm not sure what the mechanics were.

[Arbane]

The Conan d20 game had an interesting system: (I'm going from memory here, so forgive me if I've forgotten something.) Sorcerers have a small pool of power points that refresh over time, but a much larger empty pool they can fill by doing things that charge their magic - usually morally dubious at best. (Worshipping strange gods, dosing up on weird drugs, human sacrifice, and so on.) Magic in that system is rather strong, but hard to learn and you want to use it sparingly.

------------

In the modern-weirdness game Unknown Armies, magic works by being really, insanely obsessive about something - so obsessive that reality itself bends around your craziness. "'mancers" can alter reality in some interesting ways related to their magic style: Entropomancers can warp probablity, Urbanomancers have city-affecting powers, Pornomancers (no, really) can control emotions, and so on. They gain 'charges' by doing something related to their magic: Entropomancers take insane risks, Videomancers watch their favorite TV show, Dispomancers get drunk from a cup or bottle with some significance.

What's the catch?

First of all, all magicians have a taboo they can't break, or they lose all the power they've accumulated: Dipsomancers can't sober up, Videomancers must never miss their favorite TV show, Urbanomancers can never set foot on the soil UNDER their city.

Secondly, Magicians are junkies. Most of them would shank their own mother for a decent shot at Ultimate Magic Power. (Being a mundane non-magic person can actually be a big edge in this game - sanity has its advantages.)

The game is all about "what will you do for power?", and the magic rules reflect that.

-----

Over on RPG.net, someone was working on a freeform magic system with an interesting mechanic: It used a dice-pool for rolling magic effects, and non-successful dice DIDN'T go away. They stuck around as "gremlins", which would cause bizarre side-effects all around. So yes, you can cast teleportation...at the cost of making every clock in the city chime thirteen when you arrive...

-----

The original Deadlands had interesting magic for the "Huckster" class - IC, their magic worked by tricking 'manitous' (demons, pretty much) into doing magic on your behalf by beating them in a contest of skill - cards, specifically. OOC, to cast a spell, you drew a bunch of playing cards and made a poker hand out of them. The better the hand, the more powerful the spell. Drawing a Joker was VERY BAD, and the more powerful a Huckster is, the MORE cards they drew. So, more power = more risk.

[MeeposFire]

white wolf's Mage used paradox points, which built up over time.

It pretty much meant that a single use of magic had very little chance of bad side effect (unless it was very flashy or public), but continuous use had a very large chance of something bad happening.

dnd dark sun had defilers for arcane magic (which is why psionics were so prevailant), but i'm not sure what the mechanics were.

In dark sun casting an arcane spell would cause plant life to die in a radius depending on the spells power. This would make the land useless for years which is especially bad in a setting like DS which has few areas with plant life left (which was caused by defiling in the first place). Due to this the people in DS HATE defilers and if they find out you are one everybody will try to kill you unless you have the support of the local power authority (or scare/kill them). So it is mostly role playing social consequences type of cost.

[Xefas]

Kobolds Ate My Baby has the best "magical cost" mechanic. Basically, every time you cast a spell, you have to roll to see if you horribly die as per the Horrible Kobold Death Table.

[John Campbell]

Shadowrun also uses a system where you have to resist Drain damage (usually Stun, but in some circumstances, it can be Physical) every time you cast a spell, the amount depending on the power and complexity of the spell. Damage resulting from Drain can't be healed magically (and magical healing is more limited in Shadowrun anyway).

And damage is a big deal in Shadowrun... you get only 10 HP (two tracks, Stun and Physical, with 10 boxes each, actually), and you start taking penalties on all your TNs as soon as you take even one point of damage, on either track, and the penalties increase the more damage you take. And the penalties from the two tracks stack.

Missing a Drain resistance test, even by only one box, can easily put you into a death spiral where the increased casting TNs mean that you have to use more of your Spell Pool dice on the casting to be effective, which means you have fewer to resist the Drain, which means you take more Drain damage, which means your TNs go up, which means you have to use more Spell Pool dice when you cast... until you're either unconscious or completely inept until you recover - the hard way, no magical healing for you.

[GoatBoy]

The Unearthed Arcana variant, recharge magic, cuts you off from that particular level of spells for a certain number of rounds... perhaps casting your highest level of spells runs the risk of dampening your power. Do you want to unleash your most potent spell if you run the risk of having to stand there like a moron for 2d6 rounds?

Then again, one spell might be enough...

[panaikhan]

One idea for trying to slow casters down (the 'real' cost, as most damage can be circumvented).

A caster has a pool of points, equal to his Caster Level.
Casting a spell requires a number of points equal to it's spell level (which includes metamagic modifiers).
The caster's pool recovers at a set rate, until he runs out of spells.
Depending on how much you want to slow casters down, this can be points per round, or even points per minute.