Docking/Boarding Rules
Docking/Boarding a ship, be it in hyperspace, stringspace, or realspace, is hazardous at best, downright deadly at worst.
Both situations come in three types: Opposed, neutral, assisted.
Several things come into play when docking with another ship. First, and foremost, is whether or not the dockrings are compatible and can interlock. Most can, but some are difficult, and others are impossible to interlock with unless nanite reconstruction is used.
Second is speed, rotation and tumble. If a ship is doing all three, then it is going to be a nightmare to dock with.
Third... well, you get the picture.
For ease of gamesake, docking with a ship occurs like this:
A pilot makes a piloting check, DC: 20, to move into position. This provokes an attack of opportunity.
The DC is modified as follows:
Recieving ship is attempting to escape: Add opposing pilots ranks in Pilot Starship
Recieving ship is attempting to facilitate: Subtract opposing pilots ranks in Pilot Starship
Ship is tumbling: +1 per 5 RPM
Ship is rotating: +1 per RPM
Shields may not be active during this time on EITHER vessel.
Once this occurs, the ship must mate up the two docking rings, requiring another pilot starship check (like before) with the following additional modifiers:
Rings are compatible: No change
Rings are incompatible: +5
Rings are wildly incompatible: +10 or more
Once this occurs, the docking rings mate up, and the REAL fun begins.
When a ship boards another, they usually have a boarding crew ready in the docking ring airlock or ready room, armed in space armor and packing weaponry.
The airlock door will cycle, allowing entrance into the "Ringtube" (Where the 2 docking rings meet) and if the opposing one is open, ranged attacks may begin.
Boarding is exactly like storming a dungeon, and can get messy at best. All shots that miss strike the hull. A starships "frame" (which I list) gives the ships corridors hardness and hitpoints per square foot. This is deducted from.
A blast against the hull can still cause decompression if the hit points per inch are depleted, causing the entire ship to lose atmosphere if the ship does not have "combat environmental control" programming and hardware (auto-dropping doors, sealant tubing, etc).
Most of this can't be quantified with rules, and requires a lot of GM and player give and take. That's the basic guideline I use, and it's worked for around 20 boarding/repelling missions.