Hidden Player?

Is there any way to have a completely hidden player in roll20? I have a game I'm DMing with two separate groups in the same world, and I have been building up to a confrontation between the two groups. Is there any way I can have a player join the game and control his characters without the other group knowing, so that they appear to be more DM controlled NPCs?

No, there is not. Sorry. - Gauss

You _could_ lie to the other group. Tell them that he's just hanging out to observe, and check out Roll20, 'cause he's thinking of using it for his own stuff. Then, if you trust him not to mess with things that aren't his, elevate him to GM status, and it _will_ be DM controlled NPC's.

David A. said: if you trust him not to mess with things that aren't his, elevate him to GM status, and it _will_ be DM controlled NPC's. Anyone could look at the campaign info page and see the other player with GM powers, though.

I'd recommend just aiming to have your players "suspend their disbelief" about this situation, and just gloss over the facts unless they bring it up themselves. Either that, or you could coordinate with the other player via private messages and have him whisper you where to move the token and such. I'm pretty sure if he whispers you in game, nobody else will know he is doing so, and so the whole "he's just here to observe" thing will work just fine, since you'll be the one actually moving his tokens.

you might want to play around with Google plus.... if everyone is logged into googleplus, and you have someone logged onto roll20, you might be able to get away with something like what you want - you'll need to test it, but we have had issues along no knowing who was in a session because they went to the wrong place to join the game. can't say it works for sure, but its worth testing right?

also, this causes no problems if, like me, you run several games from the one campaign - i have something like 14 players assigned to one 'world' - partially because i'm planning on something similar to what you're doing here if the conditions are right.... and if any of my players are reading this, then.... well, pretend you didn't.