So I have a five strong group currently running through a mission on board a Dark eldar controlled mining cutter. After some initial pitfalls and me getting used to them not taking damage like decent easily killed PC's should, we're rolling along nicely and should wrap up within the next two or three sessions.

After that, I'll hopefully be passing on GM'ship to another player, then rolling up my own character. After that mission we'll see if anyone can think something up.

Any pitfalls that anyone sees here? I have a backlog of missions in my head just in case noone steps up...

thats a really interesting idea I often get to run but not play in games he only pitfall is the GM favouring the player whose turn it is to be GM next , also some GM's are more genrous with exp and loot than others

This is something that our group tries to do. My brother and I tend to be the active GM and we have tried to encourage the other players into giving GMing a go.

Biggest pitfall is if you're trying to include a longer term plot line or have individual player plot lines you're trying to do. Sometimes the other person's adventures can conflict or cause problems- just make sure you both know what areas are 'off limits' when mapping out your adventures.

As an aside, I've played in some very rewarding campaigns doing this, as it gives both GMs more time to rest in between sessions and the stories they (we) come up with can be stronger as a result.

Then you have to come up with a clear and concistent way of rewarding his/your character- meaning you'll probably be at the bottom of the power curve, or make sure the group votes if you give your or him bonus xp for things like good roleplaying.

Troupe Play can be quite challenging (this is where the players/GM rotate characters) but has great rewards.

The greatest reward is that adventures don't become staid or stale as the second (or 3rd/4th etc) GM brings new and different takes and ideas on the campaign path.

There are 2 ways you could handle this. First have the players generate multiple SMs and then choose what they would like based on the mission. In game this is easily achievable as the Last GM defaults to Team Leader and selects what specialities they want for the mission (Out of game the players say I want to play my Devastator/Tech marine).

Doing this allows the second (3rd/4th) GM to set a completely campaign thread that though may hint and touch upon the original thread can remain completely seperate.

If thats too much for your group, simply set parameters for each GM. 1 deals with Tyrinids, 1 the Tau and 1 the forces of Chaos. There is enough there to run 3 seperate but interlinked campaignbs without treading on each others toes.

The only thing I recomend is that the GMs set down Specifics they all refer too and may foreshodow but actual dealings with these Specifics are down to the assigned GM.
This allows the other GMs to give a little input on where they feel one part of the campaign should go as well as give fresh ideas to the specific campaign threads.

My grp are also trying a troupe style of gaming for this system. The 1st GM ran the mission 'Extraction' from the core rulebook. I have taken over now and he has rolled a tech marine my mission is about Thunders Word getting compromised whist the kill team was away. on return in the Thunderhawk the kill team have to retake thunders word from an unknown threat. After I have ran this mission we have a 3rd GM thats gonna step in and run a mission, then we shall rotate back to the 1st. Ive only ran 1 game session so far but it worked out pretty good, even though i was really 'winging it' with no idea about what the layout inside thunders word should look like. Gonna ask for advice on this in another thread as i dont want to hijack this one.