We have had players only show up regularly and then stop for a week or two each month for whatever reason. We ended up having another player take over the PC on the off weeks. Not ideal, but it worked out fine.Anyone ever do 2 players for 1 character? Now that would be something.
That hardly seems necessary in 5e to me thanks to the attunement mechanic.Players having multiple characters is a different matter entirely from players having henchmen and followers. I do allow both, but I'll only permit a player to run one player character at a time during a given adventure. So if, for example, Bob the player happens to have a 5th level fighter, a 4th level magic-user, and a 2nd/3rd magic-user/thief in his stable of player characters, only one of them ever gets to be run during a given game session. (And the stipulations given in AD&D against players with multiple characters sharing magical items between then are strictly observed: that way, Bob can't just heap three characters' worth of magical items on whichever one character is going on the adventure that week.)

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.