Goodbyeee! is a set of free wargames rules for Great War skirmish actions.
skirmish
Sulphur Post-Apocalyptic Battle
Sulphur is a set of free wargames rules for post-apocalyptic skirmishes. There’s an accompanying 28mm line of figures.
Early 19th Century Wargames Rules
The prolific Tyneside Wargames Club has produced a set of free wargames rules for early 19th Century Skirmishes.
Legends of the Feudal Times Skirmish Rules
Games Workshop’s Lord of the Rings rules set has turned out to be very flexible, spawning several commercial sets, such as Legends of the Old West and Legends of the High Seas and innumerable fan variants. Legends of the Feudal Times is a set of feudal skirmish rules originally published in the French language magazine Vae Victis. The English translation is here.
Border War Fantasy Skirmish Rules
Border War is a set of fantasy skirmish rules.