Let’s talk about the classification of character abilities as extraordinary (nonmagical) vs. supernatural (magical).
Some definitions from the Pathfinder RPG Core Rulebook, page 554:
Extraordinary Abilities (Ex): Extraordinary abilities are nonmagical. They are, however, not something that just anyone can do or even learn to do without extensive training. Effects or areas that suppress or negate magic have no effect on extraordinary abilities.
Supernatural Abilities (Su): Supernatural abilities are magical but not spell-like. Supernatural abilities are not subject to spell resistance and do not function in areas where magic is suppressed or negated (such as an antimagic field). A supernatural ability’s effect cannot be dispelled and is not subject to counterspells. See Table 16–1 for a summary of the types of special abilities.
(Update June 7, 2014: There’s been a lot of discussion about this article, particularly on the Paizo boards, and I’ve decided to append some notes to the end of the article based on those conversations. Many thanks to all the people who participated in this discussion here and in the comments, it was fun!)
(Update September 23, 2014: If you like this post and where these ideas are going, please check out the kickstarter for my Five Moons RPG, which uses these ideas. Thanks!)
Supernatural abilities are magical (unlike Ex abilities).
Su abilities aren’t like spells (and neither are Ex abilities).
Su abilities aren’t affect by SR (neither are Ex abilities).
Su abilities don’t function where magic is suppressed or negated (unlike Ex abilities, which do function there).
A Su ability cannot be dispelled (nor can an Ex ability).
A Su ability cannot be counterspelled (nor can an Ex ability).
Table 16–1 on page 555 goes on to say that Su abilities don’t provoke AOOs (nor do Ex abilities).
So really the defining difference between a Su ability an an Ex ability is “Su is magical and only works where magic exists,” vs. “Ex is nonmagical and works even if magic doesn’t exist.”
Considering that (in the core rules, at least), “a place where magic doesn’t exist” only occurs if you use antimagic field, and that’s a very, very rare effect, that means that only very, very rarely is there a practical difference between Su and Ex abilities.
3E/PF inherited a lot of “screw you,” player vs. GM crap from earlier editions of the game, such as rust monster attacks that specifically destroy weapons and armor, silence effects that negate spellcasting, wizards requiring spellbooks and therefore destroying a spellbook destroy’s a wizard’s functionality, and so on. Antimagic field is another one of these effects specifically made to negate one specific type of character ability (whether your intent is to challenge your players into overcoming a situation in a new way, or just a desire to punish people playing spellcasters). I suspect one of the reasons AMF was in 1E AD&D was because wizards got really powerful at higher levels, and it was one of the ways to shut down the party wizard and let the other characters be effective.
But AMF so incredibly rare, it’s a real corner case–like having two different types of abilities in the game, except one of them can be reversed by a wish spell and the other one can’t. AMF is rare because it’s a higher-level spell, available only toward the end of the “sweet spot” of adventuring (levels 10–12, where the game starts to give you some really cool abilities, but while the math is merely bent rather than totally broken). And it’s rare because when a GM drops an AMF, it’s totally going to screw any spellcaster players for that encounter, who has to just sit there and do nothing because their character (surprisingly) relies on spells to do things.
Given how rare AMF is, and how that one tiny corner case is responsible for defining various abilities as either “works in AMF” or “doesn’t work in AMF“… what if there was no AMF, and therefore you didn’t have to define abilities as “Ex” or “Su”? What if your character’s abilities were just… their abilities?
Spells would still be spells (and spell-like abilities could still be about 99% spell-like, just as they are now), and spells would provoke AOOs (like now) and could be dispelled (like now). But anything that wasn’t an actual spell (or SLA) would just be… an ability, a power, a whatever. You wouldn’t be able to use dispel magic on a dragon’s breath (like you can’t now), and you wouldn’t be able to use dispel magic on a fighter’s bravery (like you can’t now).
By getting rid of the idea that you have to define special abilities as either “magic” or “not magic,” you also get rid of the idea that “martial characters don’t have magic, and therefore can’t do amazing things because they’re limited to what nonmagical people can do in the real world.”
In other words, if you decide that a level 5 fighter with a shield can deflect a spell back on the caster if he succeeds at his saving throw, that would be okay, for the same reason, because you don’t have to decide “is this something a real, exceptional person could do in the real world?” If you decide that a level 10 fighter is so eager for battle that he can jump 30 feet and still make a full attack, that would be okay, for the same reason. If you decide a level 15 fighter is such a badass combatant that all allies within 30 feet of him deal +25% melee and ranged damage, that would be okay, for the same reason. It wouldn’t matter that the fighter is a “mundane” character who “doesn’t have any magic;” he could still do incredible things that bend Earth’s laws of reality or are even impossible according to Earth’s physics.
All you have to do is decide that the difference between Ex and Su is “long ago, GMs had to use AMF to fudge the game so wizards wouldn’t dominate adventures, and ever since then nonmagical characters have been paying the price for it, and it’s time for that to stop.”
(Update June 7, 2014: From here on down are my followup comments.)
I didn’t say AMF is the reason martials can’t have nice things, or even that AMF is a reason for it. I said that if you forget about Ex and Su, then you can also forget about defining whether an amazing fighter class ability is Ex or Su, and therefore forget about whether or not martials “should have to” obey the laws of physics. In other words: by getting rid of the fixation on whether or not an ability is magic, you can get rid of a (perhaps subconscious) design bias against giving martial classes magical abilities. If it doesn’t matter if an ability is magic or not, it doesn’t matter if the character class “is magic” or not… just give the class abilities that are appropriate to the theme of the class (fighting, sneaking, healing, whatever).
Getting rid of the distinction isn’t the cure to the problem, it’s what leads to the perception shift, in order to alter the design bias that leads to the problem. Much in the way that the discovery of bacteria didn’t cure disease, it allowed scientists to change their understanding of the cause of disease (away from “demons” and “unbalanced humours”) so they could finally work on targeting the actual problem (by dealing with germs rather than demons and humours).
My point is that if you don’t have to label an ability as Ex or Su, it doesn’t matter whether a swordsman is doing X with magic or skill (where X isHe just does it.