I don't know how to describe this question... .... normally you can do (highest lvl / 2) + 1 or something to find out if you can group with someone and get XP. How does this work below lvl 20? I know a lvl 1 can group with a lvl 6 and get XP, but not with a lvl 7. How do you do it for a lvl 4 for example? What is the formula? Thanks.