An Hour of Valor is a set of free wargames rules for Fantasy Skirmishes.
Rules: Ancients
Celtic Skirmish Game
From Warspawn Games: Celtic Skirmish, a combination miniatures / board game.
Nauta Ancient Naval Wargame Rules
Nauta is a set of free miniature wargames rules for playing out ancient naval battles. The files are hosted here:
Bible Bashers Ancient Skirmish Wargaming Rules
Bible Bashers is a set of free wargames rules for skirmishes in the bronze age.
Blades of Bronze Ancient Skirmish Rules
Blades of Bronze is a set of free wargames rules designed for short skirmish 15mm ancient wargames. The rules revolve around the ability of the leaders to give orders to the troops.