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.

Airland War Rules

Airland War is the successor to Steve Lorenz’ successful, commercially published Panzer War miniatures wargames rules. The rules simulate modern warfare using microarmor miniatures. You can now get Airland War as a free download.

Panzer War rules

In 1979, Steve Lorenz published Panzer War, a set of miniature wargaming rules for World War II microarmor. It was moderately successful, and in 1981, the second edition, Panzer War II was published. Having long since sold out, Steve has elected to offer these successful wargames rules free as a download.

Steve describes his set:

Panzer War is a set of war game rules simulating World War II armor warfare that will eventually use a variety of scaled miniatures. Currently it is scaled for 1/285 scaled models. Each player can assume the command of a platoon or company of troops. Panzer War includes rules covering weapons, vehicles and troops used during the conflict from 1938 through 1945. Warfare on and over the battlefield is simulated in a detailed and realistic manner. The scale being one vehicle model for one real vehicle and one infantry stand per infantry squad. The game may seem complicated at first once the basic rules are understood and experience is gained they will become second nature to the players. After familiarizing themselves with the basic rules players should move on to more advanced rules one step at a time.
And yes, there are a lot of charts and tables.

Shellshock Combat System

The Shellshock Combat System is a comprehensive set of free wargames rules for WWII, Modern and Science Fiction combat. Designed for micro scale (1/285), it features three “levels of play”: basic, advanced and “blitzkrieg” (fast play).

Able Archer Modern Combat Rules

Able Archer is a set of free wargames rules for 1/300 scale modern combat.

The author writes:

Able Archer is wargaming system, which will put players into role of company or battalion commanders durning fictional conflict in 1983. You will assume command of NATO or WARPAC ground forces. You will lead tanks,infantry but even artillery or airforces. You will be fighting in conflict that was greatest fear of every politican and commander durning Cold war. Can you defeat Soviets before they could reach the Rhine? Or will you lead final push towards the Paris as Soviet commander?

Able Archer unlike many games situated in Cold war gone hot scenĂ¡rio, is played in 1:1 scale. That means 1 vehicle represent one vehicle, base of infantry represents team and so on.
In smaller games you will lead companies, while in larger games you can command battalions or even regiment worth of troops.
Because Able Archer is aiming for wargaming Cold War Gone Hot scenĂ¡rio in central Europe you can command United States,Soviet,Czechoslovak, Polish,British,Dutch,West or East German battlegroups. You can play Able Archer storyline or even try something different like Fortress America (Soviet Invasion of USA)