Death Before Distemper is a set of free wargames rules for science fiction platoon level games.
Rules: Science Fiction
Slammer SF Rules
Tired of Warhammer 40K? Try Slammer a set of free wargames rules by Chris and Alex Nicole. The rules set is not tied to any particular set of science fiction miniatures, and there are army lists for a wide variety of troops — even Zulus! ??? (For those hordes of primitives versus superior technology games).
Fearless Science Fiction Arena Combat Game
Fearless is a set of free wargames rules that are:
… intended as a fast-paced science-fiction tabletop game including role-playing elements, with a universe full of unknown possibilities as the setting. It allows you to guide mercenaries from various backgrounds into breath-taking fights in the Arenas of Fearless. Additionally prepared scenarios and the possibility to customize your characters offer even more fun to play the game.
Dr. Who Paper Miniatures
Crow’s Nest has a very nice set of paper Dr. Who Miniatures. I’m going to print them out and make a set for my eight year old Dalek Fan.
Stargrunt 40,000
Stargrunt 40,000 is a system for converting Warhammer 40K army lists into a format usable with Stargrunt.