If compodt have completed all OSRS Nightmare Zone quests from the list above, you can get a discount of 10, on customizable rumbles. In the Nightmare Zone, you get to fight quest bosses you have fought in the past. The more quests you have completed, the more NMZ bosses will be available. Each of these three also has a normal and hard difficulty modifier. In Practice mode, you get to choose a specific quest boss to fight. This lets you practice your strategy for that fight. No experience or points are given.