experimental magic system: caster check

[AbeTheGnome]

this is the system i'm using in my game:

casters must succeed at a caster level check (1d20+caster level) vs. DC 10+(spell level x 2). cantrips are DC11.

in this system, wizards fail to cast their highest level spells about half of their attempts, but spells they've been casting longer have a higher success rate. the great thing about this system is that it doesn't require extra rolls to overcome spell resistance or determine spell failure due to armor. i simply add spell resistance to the DC, and add armor check penalties to spell rolls.

i don't increase DCs for multiple castings, but magic is illegal in my campaign, so most material components are very expensive, placing a limit on the frequency that my casters are willing to attempt to cast (as long as i keep them poor, which i love to do... makes for better roleplaying). i'm thinking about incorporating something like nonlethal damage equal to the spell level on failed castings, to add a risk factor... still undecided.

i was thinking about making a system based on skills in individual schools (i.e. 11 ranks in evocation, etc.), but it screwed up the 50/50 check that i was going for, because it's much harder to regulate skill ranks, what with ability modifiers and level +3 and whatnot. if anyone has any ideas, i would love to incorporate school-specific rolls, but i haven't figured it out. questions and comments are welcome.

 

[Pyrex]

Are you modifying SR scores at all? If not SR 11 == Immune to top-level spells.

You should probably consider modifying SR to be ~+5 to the DC when SR ~= HD+10, with a ceiling of ~+10 to the DC when the creatures original SR is >=HD+15 or so.

Also I think you're letting armored casters off a little easy; Mithral Shirt suddenly becomes a no-brainer; and very few wizards would turn down the Mithral Breastplate.

Instead of relying on the ACP, why not turn every 5% of spell failure into a +1 to DC? It's a much more direct mapping and leaves wearing armor as a hard decision.

Can you elaborate on your 'expensive' material components? The vast majority of spells in the SRD assume material components of trivial cost; how have you increased them? What about spells which as written have no material component at all?

 

[szilard]

I've been toying with a system like this, but I also add in the (bonus to the spellcaster) that for every 5 points by which they exceed the DC of a spell they can add a level worth of Metamagic (and I'd either eliminate the Metamagic feats or make them broader).

-Stuart

 

[Pyrex]

Let me see if I understand what you are proposing.

Bob the 8th level wizard casts Magic Missile. He's got d20+8 vs DC 12. If he rolls 12 or higher, he sucessfully casts. If he rolls 17 or higher, he can, oh, Enlarge it. If he rolls 22 or higher he can decide to Empower it.

Or, he could have just declared he was casting Empowered Magic Missile in the first place and rolled d20+8 vs DC 16.

Is that what you're suggesting?

 

[szilard]

Let me see if I understand what you are proposing.

Bob the 8th level wizard casts Magic Missile. He's got d20+8 vs DC 12. If he rolls 12 or higher, he sucessfully casts. If he rolls 17 or higher, he can, oh, Enlarge it. If he rolls 22 or higher he can decide to Empower it.

Or, he could have just declared he was casting Empowered Magic Missile in the first place and rolled d20+8 vs DC 16.

Is that what you're suggesting?

Yes to the first bit - but he can't just declare he was casting Empowered Magic Missile in the first place. That's no longer an option under this variant.

I'd probably institute metamagic feats in groups - where one feat buys you the ability to apply three or so different metamagic effects.

-Stuart

 

[szilard]

I'd also allow a caster to take 10 or 20 on a caster check via a ritual casting. Taking 10 would just involve extra time (or the Arcane Mastery Feat, if I continued to allow it). Taking 20 would additionally have a gp cost in ritual materials.

-Stuart

 

[Pyrex]

Yes to the first bit - but he can't just declare he was casting Empowered Magic Missile in the first place. That's no longer an option under this variant.

I'd probably institute metamagic feats in groups - where one feat buys you the ability to apply three or so different metamagic effects.

-Stuart

That's pretty harsh. See below:

[i]Empowered Magic Missile[/i]:  DC 22

[i]Chain Lightning[/i]:  DC 22

Or

[i]Maximized Fireball[/i]:  DC 31

[i]Meteor Swarm[/i]:  DC 28

Why 2* for Spell Level but 5* for Metamagic? It makes them totally useless.

Edit: Aside from the rather odd implication that there's absolutely no reason for a caster not to try and cast a Quickened spell each round.

 

[szilard]

I was originally thinking about getting rid of metamagic feats altogether and simply making metamagic a free by-product of rolling well on the casting check. That might be the way to go... so:

Fireball: DC 16

If you roll a 16-20, you cast a normal fireball.

If you roll a 21, you can Enlarge it or Heighten it (or cast it normally) or whatever.

If you roll a 26, you can Empower it or whatever.

If you roll a 31, you can Maximize it or Widen it (or Empower and Enlarge it) or whatever.

I'd probably keep Quicken Spell as a Feat that allowed you to cast a spell as a swift action by taking a penalty to your roll.

I also had this as a Spellcasting skill originally (when I came up with the +5) rather than a Caster Level check - so the numbers got higher. I think I like it as a CL check more.

-Stuart

 

[Pyrex]

That still doesn't address the problem of a Maximized Fireball being *harder* to cast than Meteor Swarm despite the Maximized Fireball having a lower save DC and (on average) doing less damage than the Meteor Swarm

A level of metamagic is not 2.5* as powerful as an additional spell level, by design they're about .75* as powerful.

 

[AbeTheGnome]

ok, let's clear up some things.

i don't use metamagic in my campaigns. in my opinion, magic is "meta" enough as it is. i'm sure that if you wanted to incorporate metamagic into this system, with a little work, you could make it mathematically logical. personally, i'm not interested.

spell save DCs are equal to the caster's roll. so, if a caster successfully cast fireball (DC 16), by getting a 21 on his caster level check, the Reflex save needed to beat the fireball will be 21. this adds a random flavor to spell-save DCs, because sometimes low-level casters will roll exceptionally well, and sometimes high-level casters will just barely roll high enough to get the spell off.

i haven't actually put my PCs up against any enemies with spell resistance yet, so i haven't run into this problem. i probably will end up modifying SR scores somehow. however, i think that SR should be a rare trait indeed, and magic items that imbue SR (magic items in general, actually) will be rare, if not completely absent, from my game. seeing as how it is so rare, i don't really have a problem with creatures with high SRs being immune to most spells.

on to material components. yes, the rulebooks assume the prices for most material components to be inconsequential. they also assume magic to be legal, and even mundane. if a dealer would be put to death for selling bat guano and sulfur, it should go without saying that he won't take that risk unless there's a substantial financial incentive. that being said, many evocation spells in my campaign require gems to cast. fireball, in fact, no longer requires bat guano and sulfur, but fire opals. they're expensive as only gems, but add to that the fact that they're highly illegal (the nobility, of course, are exempt), and you've got quite a valuable little gem. the value depends on the degree of illicitness in the given area. there are more magical societies (one, in particular, comes to mind) where magic is not illegal at all, therfore material components are much cheaper. spells that require no components have become problems. there are very few in the PHB, and i don't own the complete series, so when one of my PCs started casting flame orb or whatever it is, i was a little miffed. i'll probably alter those spells to require material components as well.

as far as armor check penalties go, yes, the mithral shirt is a no-brainer... if you can find one. the only mithral-producing mountain chain in the setting has been overrun by a particularly nasty tribe of orcs, so mithral items are relics of a bygone age. they're usually family heirlooms of dwarven families, and dwarves don't let go of their heirlooms lightly. i like the idea that a wizard can wear leather armor at no penalty. how much would it interfere with hand gestures, realistically?