Phantoms is a set of free wargames rules based on the old Avalon Hill “Mustangs” game. It’s for playing air combat games from 1960 to present. The link is to the deluxe version with all of the updates, data cards and scenarios.
Miniatures Rules
Featherstone’s Ghost Legions
Featherstone’s Ghost Legions is a set of free wargames rules for using historical figures to fight battles between the dead in the underworld.
Vietnam Air Fury Rules
Vietnam Air Fury is a set of air combat rules based on the earlier Space Fury Rules.
Assegai Zulu War Campaign
Give some flavor to your Zulu war games with a campaign. You can get the Assegai rules, and map for free.
Full Thrust Cross Dimensions
Full Thrust Cross Dimensions is a Full Thrust rules variant. It brings together rules from the various books and tries out some new ideas.