It seems like this type of dramatic structure is best recreated with "hero points". You give a lot of hero points to the wronged protagonist and then he cashes them in to get a dramatically satisfying critical hit or whatever.

Of course, combat in most RPGs is not dramatically structured--in early D&D in particular, which is the model for most RPG combat systems, combat is a war of attrition. The card game Wrasslin' tried to create a combat system built around drama, including "The Champ" (Hulk Hogan), whose sole combat power was the ability to rally heroically and discard all damage twice per game.