Crossposted to rpg.net, with bonus questions for discussion! Or chat about it here. Whatever.
So, what are the essential components of Kewl Powers? I see them as belonging to three different distinct groups, although each has some of it’s own subdivisions. I’m using D&D feats (or occasionally, magic items) as example, for familiarity.
These increase some number on the character sheet. This is typically the simplest sort of kewl power, but it can be very broad. The obvious subdivisions are Active Value Increases, which increase some number that the character uses often- for example, Skill or Weapon Focus in D&D. The opposite is the Passive Value Increase- a boost to some number that the character does not actively use, but is often an obstacle for others, or an ability that is typically rolled when called for by others (Toughness for Hit Points, various feats for Saving Throws, or even Skill Focus on Listen or Spot, since typical D&D play generally assumes that GMs, not Players, have the most influence over when Listen or Spot rolls occur.)
Since players tend to have more control over when they use their active abilities, (“I attack the orc,” or “I try to reason with the orc,”), this suggests that a given Active Value Increase is more lucrative than an equivalent value Passive Value Increase.
(Not all Value Increases are created equal! A magic item that increases a D&D’s character dexterity will aid any Dexterity roll the character makes, as well as the character’s dexterity-based skills, reflex saves, and armor class- both an Active and a Passive increase.
These change the way a certain rule works for the character. Sometimes, this simply gives the character a bonus (often by ignoring a penalty) when performing a certain action- consider the various Improved X feats that allow a character to ignore the -4 penalty for certain special maneuvers. This is quite similar to an Active Value Increase, but somewhat more complicated, and generally more narrow.
(Consider- if one removes a Value Increase, one will have to change numbers elsewhere on the sheet. If one removes a Rule Tweaker, generally, no other paperwork is necessary, except in one’s own notes about modifiers and such.)
Rule Tweakers are often built into the system as a fix on deliberately underpowered special maneuvers; by making those maneuvers require a Rule Tweaker to be used regularly and effectively (as opposed to a Special Ability to be used at all, see below), one is less likely to have ‘broken’ alternate combat options.
Rule Tweakers often resemble the other categories, and it can be hard to say where one ends and the other begins. Is a given kewl power an entirely new ability, a variant on a base rule, or a roundabout way of definining an increase to some character value?
These are the kewlest of the kewl powers; they give the character the ability to do something no one else can do. It is here we find the Cleaves, the Improved Counterspells, the Tracks, and the really crazy stuff. Cleave is the greatest example of this. No matter how high you make your attack roll, unless you have that Cleave feat, you aren’t getting a bonus free attack.
Many special abilities are murkier. Is Dodge a special ability, or just a Passive Value Increase that has a limited condition on it? I think it has more of the properties of a Value Increase. Special Abilities should be those powers so kewl, they need their own rules and new numbers to define them. Because of their nature as intrinsically different to anything else, balancing them against a numerical value is problematic, and must come down to subjective eyeballing.
So what does one do with all this?
Hopefully, looking at things like this might help one balance kewl powers in their game, should they be designing a game that uses them. While the fact that Special Abilities can’t be objectively balanced may deter some from using them, I think it’s a good sign- it means that as long as one is aware of the consequences, one is making a richer, more varied system, open to different interpretations of balance.