Paraguay is a free print-and-play wargame about the 1864 war involving Brazil, Uruguay, Paraguay and Argentina. It’s designed for 2 – 4 players.
Historia Romana is a free print and play game set in the Roman Empire. Scenarios Include:
– The Rise of Sulla, 85 BC
– The Third Mithridatic War, 74 BC
– Caesar Vs Pompey, 50 BC
– The Year of the Four Emperors, 69 AD
– The Crisis of the Third Century, 260 AD
– The Imperial Restoration, 268 AD
– Alaric at the gates, 407 AD
– The Scourge of God, 451 AD
– Heraclius and the Last Persian War, 622 AD
30 Rails is a free print-and-play roll-and-write game played on a 6×6 grid. Players draw mountains a mine and stations and then fill in the remainder of the grid with track based on the outcome of die rolls.
Dungeoneering dot Net has a nice selection of printable terrain tiles ostensibly for use with the Dungeons and Dragons miniatures game, but which would also work with any number of dungeon crawl games — of which there are many free ones available on this site.