In thinking about this, I realized that most RPGs actually use more than one of these systems for characters.Frank wrote: Resource Management.
Charges The idea is that you have a limited number of super moves that you can do. This encourages nova attacks and hit-and-run tactics, and it increases the value of get out of jail free cards like super dodge and substitute because your enemies are doing the same thing.
Rage Bar The idea is that you have to do stuff in combat to unlock your super maneuvers. Done right, it encourages people to grind in longer combats and play defensively until they can let loose with their super moves.
Cool Down The idea is that you have to wait after using any maneuver before using it again. Encourages "rhythms" where characters use moves in the same order over and over again.
Warm Up Like Rage Bar, except that it's a simple amount of time in warming up a power before it is ready to use. This encourages ambushes.
WoF The characters have access to random abilities each round, which makes them use different abilities in different rounds but does not otherwise create patterns.
Drain The characters suffer a penalty on rounds after they use their super moves, which encourages players to attempt to time their ability usage to occur as close to the end of battle as possible.
Unlimited The characters can use whatever ability they want, whenever they want. This tends to create ability spam.
Now that's basically all there is. And all of them work and all of them have their uses.
Sometimes they do it to differentiate character types, such as 3.x D&D's unlimited use swording, rage bar sneak attack charge spellcasting and occasional winds of fate item use (wand of wonder, bag of tricks, etc). Other times they do it to make the resource management more complex for a single character, such as a 4.0 D&D character's mix of unlimited at-will abilities, charges encounter, daily and item powers with potential rage bar racials and riders on other abilities.
So, my question is: is it good design or not to include multiple resource management schemes in a game? Is it needless complexity? Is it added complexity that can achieve or fail to achieve worthwhile design goals depending on implementation? If so, what schemes work best together and which don't work well at all?
Is it good design or not to allow or encourage individual characters to have multiple overlapping resource management schemes? Is this needless complexity? Does it make the game tactically richer or just more confusing to new players? Is it worthwhile only for certain types of games? And if so, what combinations of schemes work best together and which work poorly?