The Trireme Battles blog offers a set of free wargames rules for trireme battles.
ancients
Charles Sweet’s Ancients Rules
One of the legendary fathers of the miniature wargaming hobby, Charles Sweet was actually featured in a 1965 issue of Sports Illustrated in an article entitled “A :Little War Can Be A Lot Of Fun.”
These are Sweet’s Ancients rules from a 1960s era New England Wargamers Association newsletter.
Quick Ancients
Fr. Aelred Glidden, who was a frequent contributor to the late, lamented wargames magazine MWAN offers Quick Ancients, a set of free wargames rules for
Napnuts Masters of the Mediterranean Campaign
Masters of the Mediterranean is a set of campaign rules for ancients.
Naumachiae Ancients Naval Rules
Naumachiae is a set of rules for ancients naval warfare for 1/12000 miniatures.