New Magic System

[orangefruitbat]

You should make it a level check

and not a spellcraft check. Let's be honest - any spellcaster is going to max out the skill needed to cast spells. Just like a fighter would max out his melee skill if DnD used skill based combat rather than BAB.

Create a stat called MAB (Magic Attack Bonus). 1:1 for primary spellcasters, 3:4 for bards, and 1:2 for rangers, paladins, assasins, etc. Specialist wizards add 1 to their MAB when casting from their speciailized school. Clerics add 1 to their MAB when casting from one of their chosen spheres.

Also, I think it should be treated as a skill, rather than an attack/save. That means no autosuccesses on 1 and 20s. Plus you can take 10 or 20, if the circumstnaces permit. Taking 20 is basically ritual magic. (I would still have some sort of rule on the maximum spell level you can cast)

Here are some sample revised DCs (adjust to taste):

Sp Level DC*
0 8
1 11
2 14
3 17
4 20
5 23
6 26
7 29
8 32
9 35

A 1st level wizard with an INT of 16 has a 70% chance of casting MM.
A 5th level wizard with an INT of 17 has 60% chance of casting fireball.
A 7th level wizard with an INT of 17 has a 55% chance of casting dimension door.
A 9th level wizard with an INT of 18 has a 55% chance of casting cone of cold.
A 17th level wizard with an INT of 20 has a 40% of casting meteor swarm


*Extra interesting idea - spell failure to armor could simply add to the DC, rather than require an extra roll)

 

[punkorange]

I like the idea of armor and encubrence penalties applying to the casting check (or DC). I also like your idea of treating it as a MaB.

 

[JimAde]

I actually do something just like this for arcane spell failure. You don't have to roll to cast normally, but if you have an ASF, you make a caster level check with the DC based on the normal failure chance. This means that specialists get a +1 and spells that are lower level are easier to cast in armor.

Level checks also don't hose the sorcerer, since he doesn't have to have a high INT and spend feats on a skill he may not otherwise even take.

I don't think you even need a MAB, since semi-casters already have a lower caster level. Bards would get full progression if you just use caster level, but they still have very limited Spells Known.

Level checks all the way!

You could also introduce a mechanic to make "overcasting" more dangerous if you want to allow it at all. So if Bobby the 2nd-level wizard really wants to cast that fireball he might count the "overcasting levels" triple for purposes of damage inflicted. (Especially nasty if he has a backlash).

I have a system that I'm working on that does this. It allows spontaneous casters to exceed their normal limits when using metamagic feats, but at a big cost.

 

[orangefruitbat]

Bards can't cast spells of the same level as wizards. Rangers and paladins are restricted to even lower spell levels. The idea of giving them a reduced MAB is that they suceed in roughly the same proportion as other other casters.

As for backlash, here's an idea. Make the damage the final spell level (after metamagic is applied), squared. If the (spell level +1)>(MAB/2), the damage is regular damage. Otherwise the damage is simply subdual. (In case you're wondering, my formula maps to the regular spell progression for clerics and wizards. You could alwyas use another one).

So if Johnny 4th level caster risks casting a fireball, he would risk taking 25 HP of feedback damage. That's pretty nasty.

Alternatively, instead of regular damage, you take temporary ability damage. That's even nastier, though not automaticlly lethal (unless the ability is CON).

I don't think you even need a MAB, since semi-casters already have a lower caster level. Bards would get full progression if you just use caster level, but they still have very limited Spells Known.

Level checks all the way!

You could also introduce a mechanic to make "overcasting" more dangerous if you want to allow it at all. So if Bobby the 2nd-level wizard really wants to cast that fireball he might count the "overcasting levels" triple for purposes of damage inflicted. (Especially nasty if he has a backlash).

I have a system that I'm working on that does this. It allows spontaneous casters to exceed their normal limits when using metamagic feats, but at a big cost.

 

[punkorange]

The ability damage would be good. A wizard can cast spells higher than he normally could at a cost to his constitution. Say for each spell level over what he could normally cast it deals 1 con damage, if the check fails by 5 or more this is ability drain. So if a first level wizard casts a third level spell, it deals 2 con damage and three non-lethal to him, If he fails his caster check by 5 or more he takes 2 con drain and six lethal damage.

 

[gamemagi]

Ooh, I like the direction this is taking. I will keep tabs on this project and playtest it in my new campaign later today. I think I'm going to mesh in a fatigue system too. If any of you have any extra data email: gamemagi [at] yahoo [dot] com.

 

[JimAde]

Orangefruitbat: Good point about bards. I hadn't considered that. I still don't know if it's worth the extra stat, but maybe it is.

I definitely like the stat damage/drain idea. If it were me, I'd keep the drain for overcasting, and use ability damage for regular failures. That way there's a definite difference when you overreach yourself. If you just base it on how badly you blow your roll, you can get really messed up doing something your character should normally be able to do (i.e. casting spells below your normal maximum) and just rolling lousy.

 

[punkorange]

I had intended ability drain to be for overcasting only. Ability damage could go for any botched spell except for maybe cantrips though.

Sorry if I wasn't clear about that.

 

[Stalker0]

I think using ability damage for overcasting only is a good idea. In general you want a caster to feel the fatigue of casting but get over it quickly (hp). Overcasting should really drain them (ability damage).


For spontaneous casters, I would reduce the penalties for overcasting. Afterall, they already have lower chances to cast anyway due to the lower spellcraft checks they will have.

Finally, lower the hp hit that spontaneous casters take. This allows them to cast more often as is expected and makes sense. A sorc with innate magical power most of his life would be a bit better at taking the fatigue from spells than a wizard who has to rip it from some text or other place.