De Bellis Horribilis is a set of free wargames rules for The Great War based on DBA.
Furious Reason Rules 18th Century Rules
Furious Reason is a set of free wargames rules that combines Fire and Fury with Age of Reason.
Building A Medieval Roadhouse
Terrain Thralls has an illustrated tutorial on making a half-timbered, two story roadhouse. The end result is beautiful, and would be useful in a wide variety of settings.
JUGS: A Game of Big Stompy Robots
JUGS is a set of free wargames rules for science fiction combat with giant robots.
Giant robots. How can you go wrong?
The Fantasy Trip Compendium of Resources
Metagaming’s The Fantasy Trip is one of my favorite games of all time. It’s one of the core products that drew me inexorably into the gaming world. Here’s a page with a great number of resources for The Fantasy Trip.