Looking for an alternative to Warhammer 40K? Who isn't? This may be it. Even better: these wargames rules are free. Ivan Sorensen's Fast and Dirty rules also would work for modern combat.
Majestic 12 Games has these demo rules for their Iron Stars miniatures wargame. I'll let them explain:
Iron Stars is a game of space combat in an age of steam and steel. Set in a fictional universe based loosely on the writings of H. G. Wells and other fantasists, it provides a back story and ship designs from an alternate history in which the Martian Invasion actually happened, the ether is all?pervasive, and Cavorite is a reality. But, as with Starmada and other Majestic Twelve Games products, the focus is on players' imaginations; a clear and concise ship construction system is provided so you can pit your own space dreadnoughts against the likes of the Royal Navy Ether Squadron or the German Äthermarine.
Tired of Warhammer 40K? Try Slammer a set of free wargames rules by Chris and Alex Nicole. The rules set is not tied to any particular set of science fiction miniatures, and there are army lists for a wide variety of troops -- even Zulus! ??? (For those hordes of primitives versus superior technology games).
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).
Rules Crusade is a complete rewrite of the Warhammer 40K, Mordheim and Necromunda wargames rules to use the old Milton Bradley Space Crusade system. Its well done, but I'm not sure why Sean Patten went to all the effort. I'm also not sure why GW's hordes of lawyers haven't descended upon him and turned him over to the Inquisitors.
A while back I purchased a bunch of those Godzilla action figures from Kaybee toys with the idea of playing a miniatures wargame with them. I thought that I might use 1/285 armor and infantry to defend a city from the nuclear beasties. After seeing the Destroy All Monsters rules, I've been inspired to get them back out and play a game with them.
These aren't exactly free wargames rules, but if you already own a set of Warhammer 40K, this is worth checking out. Jervis Johnson has provided this page of colonial amendments to Warhammer 40K. These also would be a good way to introduce fantasy and science fiction wargamers to historical miniatures games.
Warhammer Colonials!
Miniature Wargaming is part of the "adventure games" hobby, which includes r ole p laying and board games. Wargamers recreate battles on the tabletop with toy soldiers, like a more complicated game of chess. Models range in height from 6mm to 28mm tall, with 15mm and 25mm being the most popular. There also is a growing interest in toy soldiers and military models, such as the 1/32 and 1/35 scale plastic soldiers from Conte, and Marx.
The most popular miniature wargames are fantasy and science fiction based, such as Warhammer, Warhammer 40K, Warmachine and The Lord of the Rings. World War II games such as Flames of War and Axis and Allies are new favorites. Other favorite historical periods include Napoleonics, the American Civil War, and ancients, such as Romans or Greeks. Other gamers enjoy miniature naval wargames, recreating battles like Trafalgar, Jutland and the Coral Sea.
Hobbyists research historical periods and paint their tiny soldiers in accurate uniforms. Others develop "historically realistic" rules sets or build scale battlefield terrain using model railroad techniques.
For pictures, visit the gallery.
Some of the bigger hobby companies are Games Workshop, which produces Warhammer, Wargames Foundry and Old Glory Miniatures. Wizards of the Coast produces several lines of pre-painted miniatures games, such as the Star Wars and Dungeons and Dragons miniatures games, and a historical game with pre-painted miniatures: The new Axis and Allies game. Wizkids produces a fantasy collectable miniatures game, such as the Mage Knight and Heroclick fantasy games, the science fiction games MechWarrior and Rocketmen, as well as the quasi-historical Pirates of the Spanish Main.