In my games, I have a lot of downtime between runs. I allow my characters to go about their personal lives and do things by themselves, rather than as a group. During this, one particular player has way too much to share and often invades our person to person roleplaying with his own particular actions. I have told him on multiple occassions that I will get to his turn very shortly, and that he should wait. Unfortunately, he continues with this anyway. What can I do to get this guy to stop? He keeps interrupting and making it harder for any of my other players to get anything done.

Really, beyond just making it clear that he should wait for his turn, I don't know what else you can do.

I suggest having a conversation about this with him away from the game. Let him know that his actions are detrimental to the fun of the other players, and that as GM, you can't allow one player to be a disruption that affects the whole group.

If it's possible, perhaps you could offer to occasionally run one on one sessions with the player. Behind the scenes, you know that you're just trying to give him time in the spotlight and time to get out all of his ideas. To him, he'll be getting the spotlight he seems to want, and he'll feel like he's contributing to the game.

Above all, be sure to make it clear that you appreciate his committment and enthusiasm. Be positive, but be firm in telling him that you can't let him continue to take away from the fun of the other players.

If you take the one on one sessions to another room he probably won't follow.

Pepper spray

We do that too. I've found that the key to doing this is to have everyone else that isn't roleplaying to go into the other room and either watch an old classic movie that everyone has seen before, or play some sort of video game like Super Smash Bros or whatever. Keep everyone entertained, you know.

It's crucial though that the movie be something everyone has already seen. Otherwise when you switch players to roleplay with, the other guy might want to not play and watch the movie instead! And if using video games, pick a game that's easy in and out, like multiplayer shooters and such.

The only thing I would caution someone on if they wished to use the leaving the room option is that some groups, when left to their own devices, can have trouble getting back into the game.

Some players will feel left out when you do this (not all), and it can lead to them starting up other activities that when you return, they want to continue doing rather than getting back into the game.

Like I said, this isn't a problem for everyone. I just recommend only using the other room trick if you know it won't cause any problems.

Orbital Bovine Bombardment...

I once got fed up with my group, told them that a space-cow dropped form the sky and killed them all, then walked out of the room. Since that time, the words 'Space-Cow' have the effect of making half of them repeat 'Space-Cow' in a variety of comical accents and the other half will suddenly swear blind that they were listening all along.

Ah, good old Blackjack.

tell him that behavior is the reason he will never have sex without negotiating a price first.

Stabbity stab stab.

I AM black mage.

So you don't shower often and smell like brimstone and other stuff?

Yes.

His cloths look stupid too... though he did rule hell till they kicked him out for being too evil.
You still cant kill Fighter though... loser.

Too... much... armor... *kink* *kink* *kink*

YMMV, but sometimes getting everyone drunk helps a lot. With any luck the guy who won't butt out will get drunk and get his character killed.

Once, a normally brilliant player at my virtual table got really drunk off of Beefeater gin. He seemingly passed out for a while and then woke up in the middle of a combat and cast a huge fireball at the enemy. Unfortunately the enemy was engaged in melee with the PCs...

I've had that happen to me before.

#1. Use the old 'only the person holding the magic wand can speak' trick. Ok, so it is really more suited for kindergarteners. But anyone who can't understand that it is impolite to interupt deserves to be treated like a 5 year old.

#2. Or you could try sitting down with him before your next game and explain that you all will be having some one-on-one roleplaying later that evening. Tell him that you would appreciate it if he did not interrupt during the other players' turn. If he just can't get it after a calm & clear request, see #1.

Actually, the magic wand works best for 5 year old girls. You may want to find a toy more suited to boys. Maybe a giant match-box car?