D&D rules for 5e is level 20 unless I read it wrong, which should be wrong, however, there are only a specific amount of encounters / quests which yeild exp that there is a cap somewhere. I totally disagree with this. There are too many games trying to "balance" this to keep the game "Competitive or challenging" that they forget some people just want that powerful wizard or rogue to mow down stuff. I think if a person wants to cheat, they are only cheating themselves out of their own experience with the game, or they actually like buring down things. I say leave the cap to endless almost like old school D&D and let players choose for themselves. After all aren't we accommodating for the players? Are you going to tell a customer, "No you don't need a super sized fry"? nope! "Are you sure you want a 32oz drink instead of a 16oz drink? NOPE! leave those decisions to the players. If it's multiplayer I can understand the restraint, and should due so appropriately.