Do four chars in a party cut down RAF EXP?

[Smoooth]

As I understand it it works like this:

2 players in a group split the XP from a mob 50/50

4 players in a group split 1.3(?) times the XP from a mob evenly

Thus 4 playes earn more XP overall but it is spread out so they earn less individually per mob

However 4 players WILL nuke a mob faster than 2 players - wether that balances out or not depends on how you play/wether you are questing or grinding/what classes you use/etc and also on how well the two of you co-ordinate together or if you'd have more time to play separately than together

To summarise - just do what feels best as the difference between the two situations is either marginal or dependent on other factors

This. 2 players will each get 50% of a mobs normal xp. 4 players will each get 32.5% of a mobs normal xp. So you just need to ask yourself if you would be killing fast enough in the 4 man group over what you would be in a 2 man group. Either way it would probably just be more fun to do it together.