I'm just curious about the size of other GM's groups? and how many npc's they run? I know that with Rogue Trader the later can be quite large given that the RT will probably have a ship with more than a few peeps on board! I've been gaming (roleplaying that is) for thirty years and games mastering for just about all of them! My usual group size is three to five players, though i have run the odd one on one's with a good player and had as a many as fifteen players at one time, which was fairly challenging and taxing giving the fact that more than a third of them had little to no RPG experience, but it was all good fun.

My current playtest group is made up of four people: my fiancee, my 12 year old step-son, one of my best mates, and his wife.

Generally I try to keep my groups between 3-5 people, because much more than that and no one really gets enough time in the spotlight. 4 is just right for me.

Currently running 6, the first time I have done so in years. Generally 3-5, as I find any more really hurts things unless you have a very experienced and dedicated group of players. It is still sub-optimal, but it works, and we have a great set of players with lots of experience, so it is working out well.

As for NPCs? A speadsheet full. I don't really want to count, but as Rogue Traders they have numerous officers, contacts, solders, spies, a navigator, etc.

Four people. Three gals and one guy (the bringer of doom : when things go bad, it's usually his fault).

Currently six, and I'm finding it a bit of a stretch. Included a couple of extra players last session and the situation got out of hand. Lots of yelling and nothing happening. Personally I find that five is a comfortable number to balance and design things around.

I usually find myself at the helm of 4-5.

I ran a couple of sessions with 13, but that was just crazy when it came to combat.

I've tried running games with just 2 people and man, let me tell you, in a game like Dark Heresy when neither character has a Lore skill... it is REALLY slow going when they can't make simple "I should know this about the Imperium" checks... so I would recommend against DM'ing for any group smaller than 3.

My DH campaign has a total of 10 player characters, but most players are never there at the same time so the usual setup is 3 to 5. Exactly the way I like it.

As for NPCs I have three fully detailed NPCs (Medical Enginseer, Death Cult Assassin and Entertainer) who hover around the party, sometimes coming to their assistance when asked (by players) or ordered (by Inquisitor). I have Inquisitors trusted assistant who briefs PCs and communicates with them, handling any requests for extra assistance, but never needed stats for her. Name and description is enough. As for the Big I himself... Well, the PCs see him only very briefly, maybe once in every two or three missions and meeting the Big I is always a memorable moment.

i have 6 players currently 2 of which have cohorts so 8 pc's and a whole load of npc but my group has been doing this for about the last 13 odd years so theres enough experiance to go around making my job a whole lot easier

I've got 6 and its a little bit rough some times. Though we are starting a new adventure and one of the PCs has decided to pickup a space marine out of the Deathwatch starter adventure and two others are swapping out to RT characters at similar power levels. Going to end up with an interesting group since the just recently moved into RT from DH to chase the bad guys down. The rogue trader and his ships crew are getting paid by the inquisition to transport a group hunting for one of their most wanted, who unknown to the DH pcs has done something bad to the rogue trader they hired anyway. So it should be interesting.

I'm thinking about having two different groups of players within the same game.

Group 1: Those in charge of the ship/fleet. They do whatever they feel like!

Group2: "SWAT"-team awaiting orders to board enemy ships, repel invaders, spy for the seneschal, make planetfall and scout ahead of group 1. Takes orders from group 1.

One of the groups will be about 5 people, and the other 3-4.

Has anyone tried something like this?

I run for two groups, one real group with my wife and a very good family friend, and one online with three players.

The group I play in is a group of 4.

The group I run for is a group of 9 which can get pretty hectic.

I find 4 is ideal for RT/DH, but always go for 5 as there will be on average one guy MIA.

I have had anywhere between two and five on average over the years.

As for the NPCs? If I've had time to prepare, I tend to have dozens of them running around. If not, usually around ten or so crop up.

Seeing as how Rogue trader is not a game which I am good at improving, It usually sees somewhere between 40 and 60 npcs.