Talk:Riven/SkinsTrivia/@comment-3093118-20110920044452/@comment-3093118-20110921041729

But it is a system. It is a negative cost-system (aka, you gain something instead of losing when you cast something or do something). Currently, there are 5 systems in the game:


 * Mana (cost system)
 * HP (cost system)
 * Fury (negative cost system)
 * Heat (negative cost system)
 * Nothing (no cost at all. Positive nor negative)