Su, Re, Ex

what do these little letters in parentheses mean exacly?

does it influence the game in any way? Where is the explanation of them in the books?

thanks!

Ben

Su:Supernatural Ability
Ex:Extraordinary Ability
Re does not exist to my Knowledge

There´s also Sp:Spellike Ability,the difference between those is that Ex and Su abilities can not be dispelled and work in antimagic fields while Sp abilities don´t, but thats about it.

The PRD Glossary is your friend!

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.

Spell-Like Abilities (Sp): Spell-like abilities, as the name implies, are magical abilities that are very much like spells. Spell-like abilities are subject to spell resistance and dispel magic. They do not function in areas where magic is suppressed or negated (such as an antimagic field). Spell-like abilities can be dispelled but they cannot be counterspelled or used to counterspell.

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: Special Ability Types for a summary of the types of special abilities.

The link has a table showing how each interacts with anti-magic, attacks of opportunity, etc.

Creature special abilities are of three types:

Ex: Extraordinary Ability
Su: Supernatural Ability
Sp: Spell-like Ability

All are defined and explained on the PRD at:
http://paizo.com/pathfinderRPG/prd/glossary.html

Good luck!

EDIT: Ninja'd!

Round up the usual Su Sp Ex?

I've never understood the difference between Sp and Su. I mean, I get the mechanics (one can be dispelled, the other can't). But, I don't quite get why they are different. What makes an ability worthy of Su when Sp would do just as well? To me, it seems Su is just Sp v.2.0.

So, rather than a mechanical break down of the two. I'd like to hear an ecological difference. Why are some abilities Sp and others Su? How do such abilities "evolve?"

Su is not constrained by any spell whereas Sp is just a spell but cast in a different manner. So, by all rights you could have an Su ability that far exceeds a level 9 spell whereas you'll never have an Sp ability that can do the same.

Thank you for that fellas!

You can imagine that seeing those letters all over the place and not understadning them can be really, really annoying... :)

It's also covered in the Common Terms section of the intro Getting Started/Playing the Game material, but I think a lot of people either (1) blow through that real fast to get to the "good stuff" of character classes or (2) read it once, then get into the deeper material and forget it. That whole section has a wealth of basic information that is helpful to new gamers and old hands alike.

I've never understood the difference between Sp and Su. I mean, I get the mechanics (one can be dispelled, the other can't). But, I don't quite get why they are different. What makes an ability worthy of Su when Sp would do just as well? To me, it seems Su is just Sp v.2.0.

So, rather than a mechanical break down of the two. I'd like to hear an ecological difference. Why are some abilities Sp and others Su? How do such abilities "evolve?"

First, Sp are abilities that replicate (usually in full, sometimes only partially) normal spells, except they don't have verbal, somatic or material components, nor focus or divine focus (unless a focus is part of the spell's effect itself, like Secret Chest, and it is not specified that a creature has some means by which it can avoid such need). Su, instead, are all other "unique" effects that don't replicate existing spells, don't rely on caster level, and so on.

Second, except in particular cases, Sp doesn't need anything particular of a creature; they're activated by a mental action and that's it. On the other hand, Su often (not always, it's not an absolute rule, just quite often) has something to do with a creature's body characteristics (I'm mainly speaking for monsters' Su abilities, here, of course; class features may have a different feel). For example, a Dragon's Breath, a Nymph's Blinding Beauty, a Purrodaemon's Weapon Steep, and so on. I mean, it's magic, but a kind of magic that relies on something physical too.
You could also read this (roughly) as follows: Ex = physical; Sp = magical; Su = midway of the other two extremes.

Third, something else that I forgot while writing, and the whole world shall have to deal with this loss that I'm sure it cares much about.

Spell like is kind of a misnomer... it's not really like a spell in any way save that it requires concentration. Spell like requires no movements, no power words, but you do have to focus, thus you let your guard down. Try to solve for X in your head while have a sparring match, and see if you don't get clobbered in the face.

Supernatural is also magic, but more intuitive and don't require concentration. They don't technically uniformly require any movements or words, but tend to be keyed when the creature/character does something (roaring, glaring, punching, or simply 'being' in the case that say the creature has an aura of flames). This very convenient act triggers the magic, or it's just always on, and thus doesn't need overt concentration.

Extraordinary just means that it's natural, completely physical just most things can't do it. Like constricting or swallow whole.

Spell like is kind of a misnomer... it's not really like a spell in any way save that it requires concentration.

In 3.5 D&D, spell-like abilities actually modelled specific spells. Pathfinder introduced a bunch of class features and other abilities that are "spell-like" but aren't also spells, such as many wizard specialization features.

This creates potential confusion because many of these spell-like abilities don't have a "spell level" assigned to them, which creates difficulty when determining associated effects like DCs, concentration, and dispelling.

If I remember correctly, one of the Paizo staff tried to oppose the inclusion of these spell-like effects that aren't based on spells, asking to change them to supernatural. However he was outvoted by the rest of the staff.