Wargamer and Teacher Matt Fritz has written MiG Madness, a set of free wargames rules for playing air combat in the Korean War.
The Hot Lead and Steel Sinews Yahoo group focuses on pulp-era gaming. There are also a set of playtest rules for the period, called “Noir.” Unlike other adventure-miniatures games, this set of free wargames rules is specifically focuses on the period, featuring such things as “hero points” to capture the flavor of the pulp novels.
Years ago, I played in a play-by-mail game called “Its a Crime.” In that game, you were in charge of a street gang and tried to wrest control of city blocks from the other gang leaders (players). These free wargames rules from the Lincoln Miniature Warfare Society allow you to do the same thing on the miniatures gaming tabletop.
Jim Wallman has posted the Lionel Tarr Rules for Modern Warfare on his website. Jim explains that these were
written sometime around 1959, these are as published in Don Featherstone’s original 1962 book ‘War Games’ – retyped and made available to nostalgic wargamers everywhere.
The Perfect Captain offers “Red Actions”, another in their series of superb free wargames rules. This particular set is designed for miniature wargames in the Russian Civil War. Like all of the Captain’s rules, these have superb graphics — but they are not just gratituous pictures. The thing that makes these rules so special is how tightly the graphics are integrated into the game system.