Full Command Fantasy Warfare is a set of free wargames rules for hex-based fantasy games.
Rules: Fantasy
Pocket Tactics 3D Printer Game
Pocket Tactics is a free download and print on your 3D printer game.
I think this is the wave of the future.
Table Top Quidditch
Table Top Quidditch is a set of free wargames rules for playing the favorite sport of wizards.
Wilderland Middle Earth Skirmish Rules
Wilderland is a set of free wargames rules for skirmish games set in J.R.R. Tolkien’s Middle Earth.
Ninth Age Alternate Warhammer Fantasy Rules
Given the general fan anger over the direction Games Workshop has taken its Warhammer Fantasy property, it is no surprise that fan written alternatives have cropped up. One is The Ninth Age, a a set of free wargames rules for playing mass fantasy battles. It looks very well done, and has a large number of army books.