My biggest RPG headache
The problem My regular gaming group has six players who fairly consistently can attend gaming sessions every other week. Our group plays D&D 4E, and will continue to do so for about another six months until we reach level 21, at which time I've told them I will no longer run that game. Having six players is about the maximum any gaming group can withstand, just on pure interpersonal dynamics and making sure people are constantly engaged. Recently, one of the core six players invited a friend from work to sit in on a game. It happened to be at a time when the group was facing some encounters with diverse opposition, so you had six PC's and maybe four distinct monsters, meaning you had ten different elements going off at different initiatives (I've since learned to dial that way down, favoring solo monsters or homogeneous groups). In the wake of that particular session, the whole group (myself included) was pretty antipathetic towards having another regular player,