I've been generally playing with the rule that if a player misses a session, they get no XP. But I now find myself in a situation where one player was away for the summer and missed a number of sessions and I need to level them up a bit. Do any of you award partial XP for missed sessions? I was thinking of something like 1/2 or 1/4 XP of what the rest of the players earned... Ideally I'd create a little side session for them, but time does not permit.