Here’s a set of free wargames rules for the Spanish American War using multiple dice sizes and designed for 28mm figures.
Miniatures Rules
Atteint! Jousting Rules
Atteint! is a set of free games rules for medieval jousting.
Kings of War Variant: Viking Age
Kings of War is a great free fantasy rules set from Mantic Games. Here’s a variant for the Viking Age
Space Fleet 2014
Space Fleet 2014 is a set of free wargames rules for fleet actions. It can be played on a hex grid or open tabletop, and there are rules for ship design, campaigns, sensors, and more.
Kings of War Variant: Romes’ Rise and Fall
Kings of War is a great fantasy rules set from Mantic Games. Here’s a variant for Rome’s Rise and Fall.