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.
Miniatures Rules
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.
Elan Deluxe Napoleonic Rules
Elan Deluxe is a set of free rules for playing Napoleonic wargames. Once published professionally, it now is available online. This is a very well done, and interesting set of rules. The nominal scale is 1-50, with units representing battalions and regiments.
Bloody Big World War II Battles
Bloody Big World War II Battles is a set of free wargames rules for large scale WWII battles. Each base in the game represents a battalion or regiment. The ground scale is either 3” or 6” to the kilometer. Time scale is 1turn = 2 or 1hrs. One model represents 30 or 10 vehicles / guns or half a battalion or company of infantry