James Catalano offers Bosconian D, a free solo boardgame based on the classic Namco video game. To find it, you have to scroll down to the bottom of the page, past his (very cool) retro video games downloads.
Miniatures Rules
5.56 mm Modern Era Skirmish Rules
5.56 mm is a set of free wargames rules for modern squad-to-squad skirmishes. Players represents squads on one side, while the referee controls the opposition.
A Fistful of Honey Cowboy Bear Rules
Eureka Miniatures offers a one-page set of rules for playing wild west shootouts with its teddy bear cowboy figures.
Loyalty and Glory AWI Rules
Loyalty and Glory are a set of fast play rules for the American Revolution.
Death On The Seas Ancient Naval Rules
Death on the Seas is a set of free wargames rules for ancient naval warfare. Also, Death On The Seas ship appendix.