Air War 1917 is a barebones — and free — version of Wessex Games’ AirWar: 1918 biplane combat rules.
Miniatures Rules
Heroes of Victoria’s Empire
Heroes of Victoria’s Empire is a set of free wargames rules for heroic actions in the colonial era.
Forge of War Science Fiction Rules
Forge of War is a set of free science fiction skirmish rules from Craig Cartmell. He writes that they were born of frustration with the Warhammer 40K rules from Games Workshop.
De Gre and Sweet’s Rules For Napoleonic Wargames
Gerard De Gre and Charles Sweet were pioneering wargamers who produced a number of rules sets, including these Rules For Napoleonic Wargames, which is played on a 4 inch grid.
Operational Art WWII Rules
Operational Art is a set of free wargames rules for refighting WWII’s eastern front on an operational level scale.