I have a set of players whose characters I think are great, unique, and powerful. I dont find it hard or impossible to balance around, but they hit way above their weight class. They are a group of 3, and I have found that enemies with CR between 10-12, are essentially fodder for them. I have thrown groups of 6-8 equally(ish) CR creatures at other parties of more players and have had really difficult fights. However this group over the course of one session of combat running through a dungeon, destroyed 40+ enemies, often fighting in large groups at a time. For a lark, I decided to calculate xp they would have earned using the by the book rules. Each player character would have earned 240,000 exp. For a level 11, this is more xp then they have ever earned, and is enough to kick them straight to 13 almost 14.
If you were using traditional xp rules, is it really normal for such massive amounts of xp to be gained if a party is able to tear through such a vast amount creatures? Even in the example above, if I used less but stronger creatures, the xp would wind up being similar as the higher CRs are worth exponentially more xp. If you use these rules, how can ensure you can provide a challenge, without over-awarding xp?
Best Answer
Overpowered characters will level up more easily and quickly if you stick to the standard XP rules, but there are ways to slow them down
Sometimes, your players will have brought characters that are statistically well beyond the assumptions of the game's core rules. The core rules just aren't set up to handle such deviations, and it isn't only the XP rules that fail to adequately serve the GM and the players well. Here are several tools I've personally used in the past to modulate the meta pace of the game. Each option requires player buy-in. Many players like leveling up quickly and being overpowered. So you would want to use these only if everyone agrees that they'd like the pace of leveling to be slower.
Ultimately however, the easiest solution is to not follow the standard XP rules. You can use milestone leveling, where you level the group up after specific significant encounters or when they accomplish an important goal. Or you can reward XP in the amounts and frequency that you see fit, rather than the amounts indicated in monster stat blocks. Whatever works best with your players, what they enjoy most and best fits the pace and experience you want, is the right solution.