Dreadnought Arena Combat is a set of free wargames rules for arena combats between war machines.
Miniatures Rules
American Football League Rules
Here’s a set of rules for American style football games.
Fast Play Napoleonic Rules
These Fast Play Napoleonic Rules are described by the author as DBA-esque via Fire and Fury.
Xenocide Firefight
Xenocide Firefight is a set of free wargames rule for science fiction games. Troops are organized in squads.
Blaze of Glory Wild West Skirmish Rules
Blaze of Glory is a set of free wargames rules for Wild West skirmishes.