There's also a spell point system in Monte Cook's World of Darkness (MCWoD), a 3.5e/d20 near-future apocalyptic horror setting that isn't directly tied to either the Old World of Darkness or New World of Darkness settings. (It uses a races-as-classes mechanic for the werewolves, vampires, fiends, hunters, and mages.)
The MCWoD system is a combination of Spellcraft checks and spell points.
It doesn't have a lot of examples of the spells themselves, but it lists components and costs for building them. The only spells it really lists are the rote spells. These are spells that are so commonly learned by beginning spellcasters that their spellcraft DC is lower (because the caster knows them by "rote").
I haven't compared it to any other spell-point systems so I can't say whether it's better or worse, I just know I read it and thought I'd like to use it some time.
We use a simple system:
Divine casters can spontaneously cast any appropriate divine spell.
Arcane can spontaneously cast any spell in their book/knowledge. We fused the sorcerer and wizard into one class basically.
The classes can cast the same spells / levels / amounts that they could before, so no net power has been gained or lost aside from access to more spells, but the whole Vancian memorization crap is gone. That system needs to be dumped and something more modern and interesting adopted in future RPG's. Our modifications were fast and simple, and brought casters more into line with what we typically see in fantasy and games now. IMO of course, YMMV.
Call of Cthulu d20 had a nice casting system. No spell levels or slots or max spells known, but every spell has ability and sanity damage for learning and casting it. More powerful spells are more costly.
I think its system of tomes and damaging spells would be great along with an arcanist class that gets DR against the costs, and possibly occult rituals to increase their DR further or to heal them up again. Of course, that means using the sanity system too, but that's good times as well. Spellcasting classes as written would be entirely incompatible, spells in that system are something anybody can learn and cast if they're crazy enough to want to.
Black Company RPG has a marvelous and complex skill based casting system. I've never managed to get a game of it going though, no matter how strong the group's Black Company fandom.
Black Company RGP's magic system is also available as a standalone called True Sorcery. It is however a lot more complex and I'm not sure it is what OP is looking for. It requires player preparation time in the sense that a player had better work out in advance what his signature spells are going to be. Ad hoc spellcasting requires a bit of math.
An alternative that is similar but more simple is Legends of Sorcery. Ties into existing skills a lot more and has more straightforward skill-based casting.
Jason Stormblade's solution sounds nice and easy. The only problem that I can see is players looking through 3 or 4 books for the perfect spell for any specific situation. But that is more table-control than a balance issue.
I was going to suggest Tome of Magic. The binder system gives you one or more specific suites of power, and most powers can be used at will, or with a 5 round recharge delay. Also, the vestiges are weird and a little bit un-focused. The shadowcaster is kind of ultra-Vancian, and the Truenamer is skill-based, which is good, but the powers themselves are a bit weak, especially since the majority of them are single target effects.
You could come up with a skill-based system using regular pathfinder spells. Maybe Spellcraft with a DC of 10 + twice the spell level to cast, +2 per additional time per day that specific spell is cast. And spells known like a sorcerer or wizard.
Hmmm.... DC 12 to cast at first level, where Spellcraft is going to by +8 (4 ranks, +4 Int mod for being a wizard) is ridiculously easy. Add in Skill Focus Spellcraft and they can't fail!
Maybe the DC should be 15 + 2 times the spell level?
DC 17 vs +8 They need a 9 for their first spell, which should be pretty easy, but gets harder and harder, so casters will be encouraged to use a variety of spells and not just spam out 20 magic missile spells a day.
Also, since spell casting failure is going to be an issue, maybe the Save DCs and Spell Resistance stats should also be altered? Casters aren't going to need 2 or 3 different kinds of failure all the time.
Martial Characters generally just roll to hit and then do damage; their opponents don't get saves to avoid a hit unless it's under very special circumstances (blink, concealment, incorporeality, fortification, damage reduction, etc.). And some of those only affect crits.
Maybe increase Save DCs by 5 and reduce SR by 5? Maybe by 1 per additional time the spell was cast that day? But that would involve a lot of bookkeeping, and it might be weird for a spell that is tougher to cast would also be tougher to resist.
Here's an idea.
Learning spells:
• Arcane casters need to learn spells. Wizards learn them by buying/finding them as scrolls or in prefab spellbooks. Then they need to "learn" the spell by spending one hour reading it. Sorcerers can only learn spells through direct observation (not through the written word) -- each time they witness another spellcaster performing a spell, they can make a Spellcraft check (DC = 10 + spell level?) and if they succeed they now can add that spell to their repertoire.
• Divine casters get every spell on the divine list, but must always stay very conscious of strict adherence to their alignment and strictures. You might even want to add a requirement that they must perform either a 1-hour rite (spending 10 gp in materials) at a specific time every day or a 3-hour rite (spending 100 gp in materials) every week. Breaking stricture or alignment results in a cumulative -2 penalty to all caster level checks, etc. until their next rite. Failure to complete this rite at the assigned time results in a -5 until the next rite. Remember they can only perform this rite at pre-determined times of the day or week and must expend materials.
So that's how they get spells. For casting them:
• Arcane casters have no slots. Instead they have spell points equal to their caster level + relevant ability modifier (INT or CHA in most cases). To cast a spell, they must make an Intelligence (or Charisma) check and beat a DC equal to 10 + spell level. If they get a crit (nat 20), they get to cast the spell for free. They recover 2 spell points per hour of rest, or 1 per hour of activity.
• Divine casters continue to use slots, but have to make a Wisdom check (DC = 10 + spell level, minus any penalties as described above) to receive their favor.
Oh, and for spell resistance:
As SmiloDan mentioned, it's a bit much to have double- or triple-jeopardy when using a magic as skill use system. I'd suggest removing spell resistance as it is. Instead you could have spellcasters making their INT/WIS/CHA check also compare it against the enemy's HD. That way, the spell might go off just fine, but unless it also beats the target's HD, it doesn't affect them. This also allows for targets with spell resistance to remain unaffected in an area of effect while others still get hit, and it eliminates the need for a second roll.
Another alternative would be to fold it into saving throws, and add the monster's HD to its saves against magic spells.
Currently considering just grabbing the point/buy system from the Psi book and using that.
That would work, most psionic powers have some flexibility to them. Heck, I can make a wilder with very few powers function in most circumstances, so why not? The metamorphosis powers and the astral construct powers are the most broad-ranging, but they still manage to be balanced with respect to Vancian casting.
I forgot to mention that spells would cost a number of points equal to their level. This makes cantrips free.
the standard d20 sorceror and bard (+oracle) would seem to fit the bill...?
i'm not sure if you need the rest of the game to be d20/PRPG, but D6 handles magic/force pretty well, using the same skill system as everything in D6, just with a mechanic to learn new applications of those skills. other systems are similar.
I've been working on an alternate magic system (link) for use in my own home games. I haven't implemented it yet as we are mid campaign, but the next time I run a game (or if I can talk the next GM into using it), I'll test it out.
Hypertextd20
Elements of magic revised, by Ryan nock, is a great system. Very flexible casting.
I've always wanted to try doing away with spell slots by allowing casters to cast any spell they know at the cost of one or two points of non-leathal damage per level of the spell.
This would simulate the taxing efforts of spellcasting so familiar from books and movies.
This is so simple of a solution that I figure there must be something fatally wrong with it.
I've always wanted to try doing away with spell slots by allowing casters to cast any spell they know at the cost of one or two points of non-leathal damage per level of the spell.
This would simulate the taxing efforts of spellcasting so familiar from books and movies.
This is so simple of a solution that I figure there must be something fatally wrong with it.
Off the top of my head, I see two major problems with it. First, clerics would be able to heal the damage faster than they take it. This basically grants clerics unlimited casting.
Second, the prepared casters will effectively be able to cast any spell on their spell list without restriction while the spontaneous casters will only have a few limited spells available. This will create an insanely large power gap between the classes.
Well there it is. I figured the healing would be a problem.
Just make the non-lethal damage unhealable. Or require a relatively high caster level to heal the non-lethal damage.
Or just track it as a different kind of damage (lethal, non-lethal, and mana-drain?).
And may have it cause 1 point for 1st, 3 for 2nd, 5 for 3rd, etc.