Battlestation Advanced Rulebook is the full rulebook for Battlestations Second edition, expanding upon the rules and options found in the Battlestations board game.
Battlestations is the game of heroic spaceship combat, designed for 1 - many players. You play characters of varying races and abilities, running around on your starship, using those battlestations to accomplish tasks to move your ship around on a space map and accomplish your mission. It can be played cooperatively, but the "normal" version has one person being the GM/overlord/mastermind/etc and the others playing crew.
The basic rules can pretty much be boiled down to (2d6+appropriate skill) vs target number. Anyone can roll against any skill, but Professionals get rerolls for rolls using their appropriate skill (Marines use Combat, Engineers use Engineering, Pilots use Piloting, and Scientists use Science). Your engineers run around gettting "more power out of the engines", and repairing damaged modules. Marines fire the ship's weaponry, repel boarders, and go boarding themselves. Pilots manuever the ship, fly fighters, and yell at the engineers because they need more power from the engines. And scientists scan for mission clues nad data, run the teleporters and hyperdrive, and heal their compatriots of damage.
If you've ever played and enjoyed the FTL computer game - the first edition of Battlestations predates it by about a decade. And you'll probably enjoy Battlestations.