Periplus is a free two player wargame that abstracts a battle between two fleets of ancient greek warships.
ancients
Pharaoh Rides To War
Pharaoh Rides To War is a set of rules for 20mm battles between Egyptians and Assyrians.
Pocket Civilization
Pocket Civilization is a free, downloadable solo civilization building game that’s advertised as being compact enough to play on an airplane.
It looks very cool, and the Board Game Geek reviews are favorable.
The Caveman Clash Manual
Caveman Clash is a set of free wargames rules for playing skirmishes between cavemen. There also are paper figures if you don’t happen to have cavemen available.
Impetus Basic Rules Update
There’s been an update for the free basic rules for Impetus, a set of ancient and medieval wargames rules.