The older I get, the more I like simple rules sets. Here’s one for Samurai Skirmishes.
From the introduction:
Sensō is a skirmish game, 1:1 figure scale, for 25mm miniatures. One scale inch represents six feet and one turn roughly approximates one-two minutes. Bases should be square for foot, approximately one inch. Mounted can be 1” x 2”. The game is WYSIWYG (What you see is what you get); figures are armed and armoured as they appear.
Gold Rush is a set of free wargames rules for 25mm – 28mm figures featuring Mounties in the Yukon in 1898. Dudley Do-Right and all that.
Hordes of the Empire is a colonial variant of the Hordes of the Things rules. Hordes uses DBA mechanisms.
FireForce! is a set of free wargames rules for 15mm platoon level modern skirmishes.
Serious Lemon’s Full Command is a set of free wargames rules:
for simulating battles all the way from a skirmish level with a handful of individual models through to full scale war with units totalling hundreds of miniatures.
Full Command has been designed to be setting and scale agnostic. It can be used to play 28mm skirmishes in an ancient setting to 15mm ranked warfare in a medieval fantasy setting to a 32mm heroic squad based battles in a far sci-fi setting.
Full Command is being released under Creative Commons (Attribution-ShareAlike) to allow maximum flexibility and freedom to gamers everywhere. Always wanted to play that game where Zombie Alien Pirates are battling the Savage Ape-Men on Mars? Grab the core rules, whip up a setting module with a couple of factions and you’re away.