@green @Ulfra_Wolfe @Cascadiarch
It does vary by system, though. Some actively help you create interesting melodrama and character moments, like Masks or Monsterhearts or Fate. Some just get out of your way, like D&D, and you have to do it all. Others have rules that are actively hostile to the flavor of the setting (like 1st and 2nd edition Exalted - I haven't tried 3rd).