Alright, so I'm a first time GM for RT, I've played Dark Heresy before and have DMed D&D. We're coming off of V:TM and I get opted to GM a space opera like Firefly. The PCs want to be able to sandbox try to meet ends meet by picking up odd jobs here and there while dealing with each other and their ethical dilemmas. The problem I came across is that Rogue Trader has ships with population in the tens of thousands where as my players were looking for more of a small cramped ship.

Does anyone know of a conversion for this style of game play or are we looking at the wrong game?

This setting gives us starships with populations similar to those of small cities. That's either a feature or a bug depending upon your needs. I happen to like how it allows for numerous storylines to develop that may not involve anything external to the ship. The "five guys in a small ship tooling around space" has been done in Star Wars, Traveller, Serenity, and elsewhere, and while those are all great fun I'm actually glad that this game offers something different. For such an approach to work in the WH40K, I'd suggest using Dark Heresy and giving the group something like a gun cutter. It can berth in warp-capable vessels (again, city-ships) for moving between star systems.

HappyDaze's solution is good, but you could simply roleplay the starship as a cramped place. Have a Tenebrae Maze to make getting from one end of the ship to the other a chore. Don't use morale-improving components like high ceilings or observation domes to make it seem claustrophobic, and use up every available space on the ship for stuff. Hell, you could make the ship a Reliquary of Mars, meaning that the passageways on the ship were made for servitors who wouldn't complain about cramped quarters or narrow, choked pathways. And if they want to feel alone in the vast universe, make the crew a bunch of personality-less servitors, making the Rogue Trader and his (or her) retainers the only one with functional personalities.

You're a GM; if your players want a cramped ship, use the same stats as a normal ship, but say that it's cramped. Who are they to say otherwise?

I was thinking of something like a more drastic scale between ships and personnel requirements. Like a transport ship requires less people because a lot of the optional features are removed for cargo space, the Raider and Frigate class ships are smaller ships with bigger firepower, kind of like the Normandy from the Mass Effect series to explain how they can power larger ship functions with a smaller ship, but then I came across the issue with the Space for the bigger ships as opposed to the smaller ships. Even if I can explain the power issue away, you can't put a Cruiser size weapon on something the size of the Normandy, for example, no matter how hard you try so now the firepower balance is different.

Then I thought about creating a balancing system close to EVE Online where each class of ship has a +/- to their firing capability and damage based on their hull class, using the Frigate as the standard. Essentially telling them that if they want a ship that is more capable of fighting with more firepower, they're going to have to get out of their comfort zone and start hiring some crew and somehow obtain a bigger ship.

Thoughts? Am I trying to hard to make my players happy with their Firefly theme?

Jaling Orion said:

A ship the size of Serenity would be perfect as a Lord-Captain's personal yacht. Using it to move to and from stations and planets would be fine. If you're really wanting to be a RT in this setting though, you need at least one full-on starship.

Alright, that sounds like a good idea. I might have them construct 2 ships, one standard and one where I severely reduce the space and see what they decide to put together. Any idea what would be a good stat template for a ship that size?

The Vehicle section from Into the Storm has what you're looking for.

Another option would be to use a servitor crew, rules are in "Into the Storm" IIRC.

That would get your crew numbers down.

I actually had a group want to try something similar to this concept. I planned to run it very similar to what HappyDaze mentioned. A small little cargo ship, exploring asteroids, space stations, ruins on a planets, backwater communities, mining ships, etc etc. This was all within one solar system, and it would take them weeks to months to get from one location to another (depending on how far out/close they wanted to go). Hitching a ride with warp capable vessels would of allowed them to explore other solar systems. This would of been a prelude to them getting their Warrant at rank 2-3, and receiving a full fledged starship. Thank goodness I talked them out of it, and we just started out with them on the planet Junos, receiving their warrant, and roleplaying different factions offering support/sponsorship and then asking for favors (like a merchant saying "I gave you all those food supplies at a discount, and I will continue to do so. All I'm asking for is some Eldar artifacts be sent back to me in a years time.") This lasted for about 3 months in-game time, which was the PC's waiting on their ship getting overhauled and crewed to the PC's wishes.