Argad is a set of free wargames rules for skirmishes in the dark ages and for pirates in the 17th and 18th centuries.
Bar Brawling is a set of skirmish rules for wild west barroom brawls.
Dirty Labs and Dangerous Jungles is a set of pulp extensions for the free Wild West Skirmish Set, Black West. Both can be found on this page.
Black West is a simple set of free wargames rules for skirmishes in the Old West.