Change to SR

[Rostam]

So, my DM was talking to us about a possible change to spell resistance to make it reduce spell damage more effectively.

The idea was simply to make spell resistance reduce spell damage by a factor instead of as a caster check, so SR 2 would be half damage, SR 3 would be a third damage etc. What I was wondering is what would the best way to calculate a DC for save or suck/die spells. His suggestion was to make it a d12+caster level against a DC of SR+CR+5.

So a CR 15 monster with SR 2 would have a DC of 22. This also means that for a CR of equal level, the SR will determine the difficulty of the DC in a meaningful way. An SR of 1 means you always need 6 or better on the d12 giving you about a 58% chance of success. SR 2 means you always need a 7, etc up to SR 12, which means you need a 12 on the d12 to succeed.

So that was the idea. We also thought about typing SR like DR is but didn't really talk it out all to much yet.

Any comments, suggestions or ideas?

[Dasrak]

First of all, I'm not sure what problem you're trying to fix. Why do you feel that SR needs to be more effective against direct damage spells in the first place? If anything, I find the opposite; that SR is a bit too punitive against damage-dealing spells.

With regards to direct damage, this system seems like total overkill. Most creatures have enough HP that taking half damage is already pretty insubstantial, and most of those spells offer a save to halve it again. With the more potent SR 3, it may as well read "immune to magical damage"; the spell slots simply aren't worth expending at such a vast damage reduction. Another thing that comes to mind is how do you intend to handle spells and items that grant SR? While many spells may scale based on caster level, items present a bigger obstacle.

With regards to save-or-suck spells, you've got a rather big problem. The numbers only seem to work if the spellcaster's CL is fairly close to the monster's CR. If they diverge by more than 2 in either direction, then your numbers start to get a little weird and quickly break down beyond that point. Here's one of the examples I ran through below:

Suppose we have a Vrock (CR 9, SR 20) faced with a wizard who is 9th level. By regular Pathfinder rules this gives him a 50% chance of beating the Vrock's SR. Under your system, presuming the Vrock has SR 2, that gives a DC of 16 which our 9th level wizard has a 50% chance of beating. Spot on so far. However, let's suppose this is an Elf Wizard with the Spell Penetration and Greater Spell Penetration feats. His effective CL for the purposes of beating SR is now 15. Under regular PF rules, that's an 80% chance of beating the Vrock's SR (very nice!) but under your rules he only needs to roll 1. Since SR doesn't have the "failure on a natural 1" clause, he automatically succeeds and has a 100% chance of beating the Vrock's spell resistance with save-or-suck spells.

[Rostam]

Dasrak wrote:

Suppose we have a Vrock (CR 9, SR 20) faced with a wizard who is 9th level. By regular Pathfinder rules this gives him a 50% chance of beating the Vrock's SR. Under your system, presuming the Vrock has SR 2, that gives a DC of 16 which our 9th level wizard has a 50% chance of beating. Spot on so far. However, let's suppose this is an Elf Wizard with the Spell Penetration and Greater Spell Penetration feats. His effective CL for the purposes of beating SR is now 15. Under regular PF rules, that's an 80% chance of beating the Vrock's SR (very nice!) but under your rules he only needs to roll 1. Since SR doesn't have the "failure on a natural 1" clause, he automatically succeeds and has a 100% chance of beating the Vrock's spell resistance with save-or-suck spells.

That's a good point. I liked the damage reduction part cause I have sr and the dm uses casters a lot. Didn't think to do the math at extremes, silly me. Glad I can now say I don't like this idea. Thanks

[Can'tFindthePath]

My group has been playing since 1st Ed. AD&D, and when we came into 3.0 we had a really high-level group. We saw with the SR arms race from the top down. 3.5 calmed it down a bit, and these rules are carried into Pathfinder, however, we know where the path leads when it comes to SR. And we didn't like it.

Consequently, we decided to ignore SR altogether; but this is not satisfying either, as some critters are just supposed to be resistant to magic.

So, here is our latest take on SR: We divide SR by 5, rounding down, and make it a resistance bonus against spells and spell-like abilities. But, it also acts as Damage Resistance vs. spells and spell-like abilities equal to the SR divided by 2, round down.

Admittedly, we haven't gotten any real playtesting on this, as our current campaigns are all lower level. But, it's something to try.

Note for clarity: in this rule, SR no longer causes a caster level check to penetrate.