American Civil War Riverine Actions is a set of free wargames rules for ironclads, tin-clads, cotton-clads and all the fun and unique ships that plied the rivers of the United States during the ACW.
Gladius and Pilum Ancients Rules
Gladius and Pilum is a set of free wargames rules for battles set in the 500BC to 500AD era. They’re designed for 15mm miniatures, with one figure equaling 50 men.
The Lord of the Rings Express
Lord of the Rings Express is a free print-and-play game based on the cooperative Reiner Knizia game. The express part is that it plays in a more streamlined, faster fashion without apparently losing the feel of the original.
By The Gods Ancients Warfare Rules
By The Gods is a set of free wargames rules for ancients warfare. The rules are relatively uncomplicated, but do have some modifications for “national characteristics.”
Origins of World War I Board Game
Origins of World War I is a free print-and-play game by legendary wargames designer James Dunnigan. The game was re-implemented as Origins of World War II, an Avalon Hill game now long out of print. From the description:
A political/strategy game in which five players represent the five major nations in pre-World War I Europe. They must compete against each other to achieve each nation’s ‘national objectives’. While actual war is not allowed in the game, the play should show quite clearly how tensions developed to such a high pitch in 1914.