GURPS Spaceships: Building a Space Opera Setting

 In order to make a consistent and plausible setting you need to outline setting assumptions and try to make them make sense and be internally consistent with the setting.

My first step was to determine what form of FTL I wanted and how it works as well as regular space travel. I wanted to use the same core technology if possible so everything blends together. I went with grav-tech and two variations of Jump drives.

Reactionless drives based on gravity manipulation, not the classic push or pull but by bending the spacetime curvature so ships basically fall in the desired direction and that curve can be as steep as desired for higher acceleration. No grav compensators so that pilots dealing with extreme acceleration is a thing.

The FTL portion is bending spacetime so much that ships fall through space itself, only to reappear days later elsewhere.

This led to TL10^ with Standard and Hot Reactionless drives and a custom FTL drive that used various switches.

How Big Are Ships?

My next big step was to decide how big ships would be. I looked at the material in GURPS Spaceships, specifically the Hull Size Table (p. 9) and some example starships.  Then checked out tonnages and size of real world ships to give me a range of ship classes.

Smallcraft: SM+5 to +7 for shuttles and personal transport.

Corvette: SM +8 commercial, escort, survey, and light patrol ships.

Frigate: SM+9 As corvettes. This is the largest SM where most ship systems do not require a dedicated workstation. This makes Frigates optimal for PC ships where a small crew can easily run the entire ship.

Destroyer: SM+10

Cruiser: SM+10 to +12

Battleship: SM+12 to SM+15

Carrier: SM+11 to SM+15

So Frigates are likely the largest PC controlled merchant ship. Most ship systems do not require dedicated crew so a bridge crew can handle most things. 

• Control Rooms have six workstations, plenty for most PC parties. 
• Each Habitat space includes 20 cabins, covering the full crew with plenty left over for passengers or other facilities such as labs. 
• Hanger Bays can handle 100 tons per system, allowing for a shuttle or fighter craft.
• Each Cargo Hold can hold 150 tons, not a large amount but ok for high value cargoes and a ship can of course have more than one cargo hold.

These guidelines let me focus on what size ships to build a good starting sample set. Star Heist is not intended to be a military campaign so the PCs will likely have a SM+8 or SM+9 starship and compete with larger merchant vessels in the Destroyer or Cruiser class that have higher overhead and crews. I also intend there to be plenty of "independent" merchants using SM+8 or SM+9 starships.

Ship Designations

On earth ships are registered with certain designations. This can be useful for players to quickly identify a ships purpose. I will assign ships transponders that broadcast the designation, manufacture, and the make and model. This will speed things up in play, give PCs with appropriate skills or databases to know roughly what a stock model of the ship they face is capable of, and I hope be immersive. Certainly it feels better than just giving a lot of mechanics and statistics.

For example they encounter an Eagle model courier ship made by Stardust Enterprises.

I can then tell them on a successful roll that it has a UV spinal mount, 1 cargo hold, rated for FTL6/6gs, has a hangar bay, and one electronics compartment - usually ECM.

Of course that just tells them the stock design, they need a good sensor roll or closer examination to find the after market modifications or perhaps even manufacturer options like the spinal mount is Improved UV laser with a gravitic lens and the electronics compartment is really a Tactical Array.

So far I have CX (Courier); LB (Life Boat); MV (Merchant Vessel - mega corp); RC (Research Vessel); TV (Trading Vessel - independent); and military designations CV (Carrier Vessel); DD (Dedicated Destroyer); EV (Escort Vessel).

I'll add more later. Transponders will also list the name of the ship (good for Reputation and maybe knowing the captain), and the owner if its a megacorp or military ship. Transponders can be hacked and military ships can turn them off to be more stealthy, but most ships will broadcast them for legal purposes - much like modern ships and especially aircraft.