Threat is a modern micro armor game. The authors write:

THREAT is a modern-era miniatures wargaming ruleset that was designed to be a fast-moving fluid game of modern tactical ground combat using 1/285 scale miniatures.

THREAT is a very realistic simulation of the deadly modern battlefield. Combat is simultaneous, for this reason a referee is recommended to direct resolution of the firing and resolve line of sight (LOS) problems. Each miniature represents a one-for-one ratio of personnel and equipment. Aircraft may represent multiples of aircraft of similar type.

Unlike other game rules, THREAT does not use individual vehicle charts, rather it uses charts for each weapon system that modern vehicles employ. In this way any number of vehicles with different weapons mountings can be utilizied without having to create new charts.

Steel Rain Sci Fi Rules

Steel Rain is a set of rules for 1/300 scale science fiction miniatures.

Iron Cow 1/300 Science Fiction Armor Rules

Iron Cow is a set of simple rules pitting companies and battalions of science fiction and armor against each other.

Micro Armor Devastation

Micro Armor Devastation is a set of fast play miniatures rules for land and air combat from World War II onward. They’re very nicely done in a pdf format.

Fistfull of Tripods Rules

Ty Beard’s Fistfull of Tripods is a set of free wargames rules for fighting battles from H.G. Wells’ War of the Worlds. It is a tactical level game, where one stand is a platoon. I’ts designed for 1/300 (6mm) scale figures.

NOTE: This is an updated URL. The old one was no longer working.