The Manchester Area Wargames Society offers a set of free wargames rules for ancients.
Miniatures Rules
Simple World War II Naval Rules
This is a set of simple one page rules for WWII naval warfare.
Action Figure Combat Rules
Action Figure Combat is a set of free wargames rules for games with 1/8 inch action figures. From the author’s introduction:
Action Figure Combat is a ‘Beer and Pretzels’ style game that is fast and easy to learn. It is a set of game rules for use with 1/18 scale (3.75”) action figures. Now you can play a game with your military action figures and emulate your favorite cartoon and comic book battles. The focus is on small unit tactics involving a dozen or so action figures on the table with the option of one or two vehicles.
The Scot and Welsh Wars Miniatures Rules
The Scot and Welsh Wars is a set of free wargames rules for medieval battles circa 1277.
Take That Camel Up The Khyber Pass Rules
Take That Camel Up The Khyber Pass is a set of rules for colonial British versus Afghans in 1894.