Spell failure?

[blargney the second]

I assume this has something to do with getting an incorrect value on an Appraise check? I think by the rules the spell just wouldn't work.

It'd be sort of entertaining to make the Resurrectee come back at 90%.

-blarg

 

[shilsen]

The clearest answer I know of is on page 171 of the PHB, under "Spell Failure." Based on that, it seems clear to me that if you try to cast a spell without one of the necessary components, the casting fails and the spell is wasted.

Since that section refers to situations where the "characteristics of the spell" can't be made to conform to the conditions, I see that as applying to the spell after it is cast. The way I see it, if you don't have the correct components, you can't cast the spell in the first place.

To use an analogy, if one views casting a spell as firing a gun, I see the pg.171 section as referencing what happens if you fire the gun against a target immune to gun-fire, or with a wall between the two of you, etc. Whereas the bullet would be the components, without which you cannot fire the gun in the first place.

That being said, I think your interpretation is just as reasonable a take on things.

 

[AuraSeer]

I impose a spell failure chance, based on the proportional difference in value between the actual component and the required one. If your component is worth X percent of the required value, you have that same percent chance of having the spell work.

For instance, if the spell requires a 10k gp diamond and you try to use one worth 5k, you have a 50% chance that the spell will work. If you try a 100 gp diamond, you'd have only a 1% chance it would work (a 99% chance of failure). Failure on this roll still expends the spell slot and consumes the component.

A caster taking advantage of this will still pay just as much for components, over time; when using cheap components he'll have to make more attempts, and it'll all even out. I just think it's interesting for flavor purposes.

 

[blargney the second]

I suppose you could also suck the rest out of the caster's soul with an appropriate XP cost covering the gap.

-blarg