As a slayer, you a rolling ball of unstoppable rage, and your class mechanic reflects this. There is a gauge above your characters action bar that displays your level of fury. Green is the base level, you receive no bonuses or penalties at this level. As soon as you enter combat, you start gaining rage, and soon you will enter the second level, Furious! When you are furious, you deal 25% more damage and will be able to use some abilities that are only available when furious. If you keep on fighting, eventually you will become Berserk! When you are berserk, you deal 50% more damage, but your armor and resistance are also reduced by 50%. When in this state, you can do some serious damage, but you are also even squishier than before, so be careful. Paying close attention to your Enrage bar is key to playing a slayer correctly.