Elf Witch said:So just because you run the game gives you the right to suck all the fun out of it for everybody else?
Right? Why yes. Running a game gives you the right to do anything you want -- it's the right of an artist to create what he sees fit, critics be damned. Of course, if nobody wants to play with you/look at your paintings/listen to your songs, your right is not so useful.
Elf Witch said:A good DMPC needs to be played with a subtle hand.
All characters should be role played, that is, the character should be played as the character, no more, and no less, whether that character is a woodcutter, a seer, or a guy who ends up joining the party.
If you take the attitude that all characters are characters, it's easy for NPCs to join the party and become something more . . . the only real difference I've seen is that they tend to be more transient than other party members, more likely to be dropped off after an adventure.
Hmmm, in a game where D&D is cooperative role-playing and "ars artis gratia" -- the game for its own sake -- asking an NPC to join the party/letting the DM join in doesn't seem likely to "harm" any of the partcipants.
But in a game of powergamers where the goal is beating everyone else by having the best build, then I can see the objection. Especially if the DM cheats in his own favor.