pemerton said:
I also think the suggestion that Saving Throws need to be kept distinct, because they apply to things other than magic, is a bit of a red herring. At high levels where SR tends to kick in, it's not as if monsters are having to make a heap of saves against poison, pit traps etc.
While I see your point, it should be noted that while MONSTERS aren't making a heap of saves, PLAYERS ARE. One of the benefits of the 3.X system is that monsters obey the same rules as players, at least in the main. Changing this is fine, but make sure you understand the more subtle ramifications as a DM and be prepared to address them. One of the things that gets driven home again and again is that monsters are not players...because of this, they get a generally sweeter deal in some ways and not in others (because at the end of the day, they cardboard cutouts...most monsters don't get to use all of their abilities and only engage in a single combat in-game...EVER).
pemerton said:
And when it comes to non-magical abilities like Stunning Fist, there's no obvious balance reason why SR should not apply to this, but should apply to spell-caster class abilities that produce the identical effect.
I suppose that depends on how you mean balance. Stunning Fist is one of the monk classes best features (although technically now it's just a bonus feat); conceptually it's a strike to the vitals or some similar attack that effectively knocks the wind out of an opponent. It's not a magic effect at all, so I'm not sure how it enters into the discussion any more than having Dodge contrasts with Mage Armor. If it were to be classified, it would be an Extraordinary ability.
pemerton said:
There's no denying that having so many variable to model the same ability allows for complexity in monster and character design. But it does give rise to doubts as to whether any coherent interpretation of that design in anything like real-world terms is possible. And it is not an obvious virtue in a rule-set to model the same thing in so many different ways - for a start, it makes mechanical balance that much harder to achieve.
Well, I think you're mixing-and-matching, here. Tumbling is a conditional ability, for example, that doesn't change your AC, merely adjusts whether or not you are eligible for an attack. DR is primarily meant to show that some creatures just selectively ignore damage entirely (such as a fire elemental ignoring fire damage). This is not the same as saying there are two alternate forms of magic defense; SR and saves pretty much cover the same territory, while something like Tumble, Dodge and DR do not.
Which again brings us back to the idea that SR is
not necessary, if you don't want to model magic in the fashion that core D&D does. I disagree that what SR protects against is unclear....quite the contrary. SR protects the creature/character from DIRECT magical effects. In the case of Acid Arrow or Scorching Ray, the spell is the delivery system, not the damaging effect....and the spell requires a separate roll to be successful. Magic Missle, by contrast, never misses (though it can be absorbed, it doesn't fail). There, the spell IS the damaging effect. No rolls are made, there is no chance for failure, ever. Acid Arrow and Scorching Ray do higher, more variable damage in return for that failure chance. The same idea applies to Flaming Arrow, for example, where the spell affects the arrows, not the target.
Is this is a useful or meaningful distinction? Well, that's left as an exercise to the reader. Clearly it isn't necessary, but I like the level of granularity that the current system offers...and I haven't heard a compelling enough counter-offer, system-wise, to take issue with it. If the alternative is monster entries that are greatly expanded to list all of their potential special saving throw circumstances, I'll stick with what I've got.
