Can My Soldier Shoot Yours Daddy? is a set of free wargames rules for wargaming parents to play with their toddlers.
Warblocks is a set of free wargames rules using Jenga blocks as troops.
Rabbidgerbal Wrestling! is a set of free rules for professional wrestlers in a ring.
Here’s an interesting bit on one gamers’ expansion of the Memoir ’44 system to a variety of conflicts.
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.