Custom magic system

[Aleolus]

OK, I have never really liked the spells-per-day system that D&D uses. It's been explained to me in a way that makes sense and is logical, I just don't really like it all that much, so here's a different system that I came up with, and would like to get some critiques on. First, I'll describe it from an 'in-game' perspective, then I'll explain how the mechanics work.

Every person who utilizes magic channels their power from a specific source. Clerics and Paladins channel it directly from the Gods, Druids and Rangers channel it from nature, Wizards get it from the arcane weave that ties everything together, Sorcerers from their extraordinary blood, and Bards from the power innate in words themselves. Because of this, those classes have an innate tie to the powers they gain power from, which they then must draw that power from, and shape it into whatever form they desire.

Now, for the mechanics. First off, there is no pre-made spell list. Everyone who uses magic uses it just a little differently. Casting spells is a three part process. First, you decide the effect you want to create with magic, and describe it to the DM. He then decides how difficult it would be to pull that off, and how much energy it would require, choosing an appropriate DC. You then make a Concentration check at that DC, followed by a Spellcraft check, using your primary casting stat as the ability mod. The Concentration check determines if you can draw out the power that you need to accomplish what you're wanting to, the Spellcraft if you can shape it into the form that you want. Now, there are dangers in doing it this way. If you fail your Concentration check, you can't draw the power you need and are mentally fatigued (-2 to all Int, Wis and Cha based checks, as well as Concentration checks). If you succeed at the Concentration check, but fail at the Spellcraft check, then you've pulled off the energy you need, but you didn't shape it properly, resulting in a backlash that deals nonlethal damage to you (basically, it explodes in your face). If you succeed at both, then the spell comes off, just the way you wanted it to.
Now, for describing the spell, you describe the effect from an in-game point of view, and the DM determines appropriate die damage and/or other effects. If you have something specific you want it to do (like negative levels or the like), then say so, though that will probably increase the difficulty.

[Claudius Gaius]

Those systems work, but you have to be very careful to be consistent and unbiased. It's usually best to either keep your own notebook, or have everyone keep notebooks, and record the effects, DC, and discriptions you create. That way it won't vary wildly when someone in a recurring situation wants to do the same thing they did two weeks ago. As a side benefit, everyone will soon be building their own lists of favorite spells and spell discriptions.

Secondarily, you need to specify if people can back out after they hear the DC's assigned and determine if that takes an action. If not, you'll have to sit through dozens of ideas before some players come up with something they want to commit to. If it does, players may miss quite a few actions because they're ovarambitious.

For some quick thoughts:

Be prepared to have high-skill characters use magic for everything, including tying their shoes.

Also be prepared to have people finding ways to stack the relevant skills until they turn into junior godlings.

Finally, limitless casting of lower level spells - since characters may be able to "take 10", and skill rolls do not automatically fail on a "1" in any case - may have drastic effects on your world.

[Arkhandus]

Yep. When you can use magic to do absolutely anything, and have managed to pull off a particular magic trick before with ease, you'll know that you can probably always do it automatically without fail and without any drain/loss. Fling minor magic bolts that deal damage like a fighter's main attack, at will, or hover around everywhere, or whatever. At the very least.

You don't really address casting times, the differences between different class' degree of magic focus (I imagine a paladin or ranger must wait until 4th level to use any magic at all, and will face much higher DCs than a cleric or druid to accomplish the same magical effects, while bards have a somewhat higher DC than a sorcerer or cleric for such purposes, for example). Like, I dunno, an extra +5 to the DC for bardic magic, +10 to the DC for paladin or ranger magic.

And the DCs should probably be based on the caster's power source; a druid should have a very hard time discerning the powers of a magic item, or disintegrating a foe, or teleporting, or plane shifting, if they can do it at all, since they're drawing on natural forces for their magic rather than arcane power or deific intervention. For example.

And, really, I don't much like the thought of a magic system that's basically boiled down to "DM's fiat and player's creativity/smarts at any given moment."

Having some well-defined base effects with DCs and such, that can be objectively looked over beforehand (rather than just guesstimated at the table spontaneously, which could be really tough or time-consuming for some effects), would be best. Something like the epic spell seeds, but less stupid (only the basic idea behind them is decent; the designers' execution is horrible!).

And as Claudius said, you need to figure out if the spellcaster can decide whether or not to go through with a spellcasting attempt after hearing what you've placed the DCs at. Though it may still take up the normal casting time in actions, a caster should be able to tell when they might be getting in over their head in terms of magical energy drawn or the difficulty in trying to keep it under control and shaped properly.

[Aleolus]

Well, the first portion, where the player says what they want to do, and the DM decides how difficult it would be, that takes no time at all in-game, that's just a quick "How would this work?" "Quite well, but it would be pretty tough to pull off." "Well, how about this?" "Perfect. Roll." type thing. And the exact DC would vary based on class and circumstances (creating a giant ball of fire is easier in hot, dry conditions, but hella hard in the middle of a monsoon), but keeping a log-book would be a good idea, for the base numbers.

[Primitive Screwhead]

I agree with Arkhandus that magic via DM fiat is not a good system unless you have an exceptional DM...

I know I am not good enough to pull that sort of system off fairly as a DM, but good enough as a player to get some really nasty effects into my notebook...

May I suggest Elements of Magic: Revised? The system has a bit of a learning curve, but it codifies the effects of cost of the spells using a spell point system to build the effects the caster knows into a spell. Casters get a pool of points per day and can use them in any fashion they want.

I love the system.. flexibility and imagination unleashed withough the certainty of results.


The Elements of Magic: Mythic Earth version is designed more for D20 Modern, but uses a skill based casting system.

[Claudius Gaius]

Best to keep the fields relatively narrow for improvisational magic too. It helps keep everyone distinct. I put in some options and classes to use it back in first edition, but these days we mostly use Eclipse to customize everyone and let the poeple who want to build improvisational casters do it that way.