Why is SR necessary to the game?

[Dracomeander]

What you seem to be confusing is the difference between being able to throw off the effect or part of the effect of magic (saving throw), the ability to ignore the effect of the magics of a being with a lesser ability at controlling magic (spell resistance), and the ability to totally ignore certain magical effects due to an innate nature of the creature being targetted regardless of the skill of the magic wielder (immunity to certain effects).

They are three very different things that sometimes appear to give the same effect. However, the mechanics need to be separate because a single mechanic can't cover all three situations.

 

[frankthedm]

What do you think are the fundamental reasons (mechanically or otherwise) for Spell Resistance to exist in the game?

Because there are creatures resistant to mortal's magic.

Since all it does is lower the chance that a certain creature is affected by a spell, why couldn't we just have Saving Throws?

SR always negates effects, saves sometimes only reduce them. There have always been spells a with save for half. Saves can [or at least should be] made harder. How well one can move has no bearing when the magic can't touch them.

What does SR achieve that the Saving Throws cannot, even with a minor tweak?

SR tells a caster with an impossible save DC thermo-nuke spell "No". It instill humility in arrogant wizards and provides a wake up call to multiclass dabblers and UMD’ers.

 

[Henry]

If you had an Evasion-type effect for all three saves, then you wouldn't need SR -- just a high save and an "all or nothing" proposition for the spells. As it is, some spells don't allow saves to avoid their effects; SR creatures are typified by NO spell getting a free ride on them.

 

[Li Shenron]

Here's the logic, maybe:

As is, SR allows the game to have some spells more effective than other to certain creatures. This is done by having spells with no save where SR applies.

This way you have another variable to manipulate how creatures are affected by magic.

Having one more variable could be good, but isn't definitely necessary.

More variables into the fray means more complexity, which is good or bad depending how you look at it. That we have only 2 rules for "resisting magic" could be too simple for someone who likes complex games, and too much for someone else who likes simplicity. How are you so sure that 2 is the right amount of complexity?

 

[superkurt13]

SR gives high level monsters a chance against high level wizards. otherwise what would stand in the path of a 20th level wizard with an empowered, maximized, split, twinned magic missile?

 

[Li Shenron]

SR creates a simply, separate mechanic for modeling a different kind of resistance. Using just saving throws, you cannot model SR. Evasion or better saves doesn't do it. It's similar, but not that same, and trying to hack it into being the same will just make the saving throw mechanic much more complex with lots of special rules. Consider a couple of examples.

Explain to me in a reasonable amount of detail how is it a "different kind" from a general (non-related) point of view.

Intuitively, at a description/explanation level if you wish, there is no difference between ST and SR, they are both just a chance of avoiding magic!

First, I don't see a fundamental need to "model SR" with ST. We could introduce a third kind of resistance to magic with its own ruleset, so that it cannot be modeled with the current rules of ST and SR: would that become necessary just because of that? I don't think so...

1. Slay living and fireball. These cannot both be modeled with evasion because evasion only works on reflex saves. Yet, someone with SR can ignore slay living entirely while somewhat without SR cannot. More importantly, evasion doesn't work in all cases, but SR does.

Don't think about what you actually have in the current rules. In another ruleset without SR in the first place, there could be an Evasion equivalent for other saves, or Slay Living could have a ST (and by the way, I always thought it ought to!).

2. Cure spells. Trying to cure your buddy who has SR is a big deal and without SR, it almost becomes intractable.

...and why is that a good thing? First, it's a consequence of SR and not a reason for the need of SR in the game, and second if lots of gamers actually "forget about it" maybe it's because it is a not-so-nice consequence.

3. Impassable barrier spells. A blade barrier blocks a hallway. A creature without SR will take damage trying to get through. A creature with evasion may take damage or may not. A creature with SR may take damage or may not, and still has a chance to take only half damage. A creature with SR and evasion has two chances to ignore the damage (but without SR, his evasion or perhaps even improved evasion has issues depending on how you otherwise emulate SR). There are other barrier spells like wall of fire where no save is allowed so how do you work out the SR? Wall of sand might be another (from Sandstorm).

Mah, it doesn't convince me at all. It might be nice to the game to have spells that have 3 possible outcomes such as (a) full effect, (b) partial effect, (c) no effect. Then why can't you simply make it part of the ST result? Could be in the BB spell description: fail by 5 or less and get partial damage, fail by more and take full damage: here's the same result with one roll less.

And the "two chances instead of one" idea... does it really hold? What matters is the % total chance, it doesn't matter if you have to roll 1 die or 10 dice to know the result.

 

[Li Shenron]

SR gives high level monsters a chance against high level wizards. otherwise what would stand in the path of a 20th level wizard with an empowered, maximized, split, twinned magic missile?

A creature with a very high ST, where in a game without SR even Magic Missile might allow a ST.

 

[satori01]

A Saving Throw feels different than SR. SR is in effect magical armor. The overall mechanic I think is easier to use than remembering that certain creatures have in effect the Mettle and Evasion special qualities.
Moreover, for creatures like Outsiders and Dragons, I can see it being much easier for a spellcaster to defeat the SR, then to boost the save DC's up to a level where the spellcaster can get a consistent result.

If suddenly MM, or Eldritch Blast gives a Reflex save to say...the Ancient Red Dragon Wyrm used at GenCon...good luck trying to hurt that thing.

Nah...Saving Throws instead of SR, adds an extra layer of unneeded complexity to the basic "to hit" mechanic that is SR, everyone is familiar with.

 

[Infiniti2000]

Explain to me in a reasonable amount of detail how is it a "different kind" from a general (non-related) point of view.

Intuitively, at a description/explanation level if you wish, there is no difference between ST and SR, they are both just a chance of avoiding magic!

No. SR is ignoring magic. Saving throws are avoiding/getting out of the way/shrugging off magic. There's a significant difference. A dragon with high SR may be so confident in his SR as to just walk through a wall of fire. Isn't that a situation that you find interesting? That's not a mechanic you can model with saving throws.

First, I don't see a fundamental need to "model SR" with ST. We could introduce a third kind of resistance to magic with its own ruleset, so that it cannot be modeled with the current rules of ST and SR: would that become necessary just because of that? I don't think so...

Wait a minute, think about what you're saying here. You want to remove SR and replace it with an exact duplicate? How does that change anything?

Don't think about what you actually have in the current rules. In another ruleset without SR in the first place, there could be an Evasion equivalent for other saves, or Slay Living could have a ST (and by the way, I always thought it ought to!).

You have to think about what you have in the current rules in order to determine the fundamental mechanical reasons for a mechanic. I don't see any other way. More importantly, you have to think about them to tweak anything. You can't create/tweak rules with your head in the sand.

 

[Infiniti2000]

A creature with a very high ST, where in a game without SR even Magic Missile might allow a ST.

ST's are not a good mechanic IMO to model multiple levels of success. The ST + SR gives you three levels: completely ignore (SR), and two different possible effects for the ST based on success or not. By removing SR, and using it to modify the ST, you artificially increase/decrease the success on the other two options in order to introduce a third. This is especially true if you try to introduce some modified version of evasion (to work on non-Reflex saves). It complicates the saving throw mechanic, as well, and for a game that is supposed to be simplified, particularly towards the player, that's not good. It will not make much of a difference for the average reader of a Rules forum, but I know there are many players (and even DM's out there) who think that even D&D's simplified ruleset is too complicated.

So, let's take a crack at it. Consider slay living. It allows a Fort save where success means you take some damage and failure means you die. It also allows SR where success means you completely ignore the spell. For simplicity, let's ignore all other things like AC, crits, death wards, etc. In order to use the ST mechanic only (multiple people here have suggested it), you would need to create a multi-level ST. As you decide on your rules to handle that, I'm sure you'll quickly see how poorly it models the existing mechanic, meaning that the existing mechanic is a good one.