The Portable Wargame is a sort of mini-movement in the community: a series of user created rules for games based on checkers boards. They all look interesting and fun. Here are the rules for the modern version.
modern
SNAFU Modern and Science Fiction Rules
SNAFU is a set of free wargames rules for Modern and Science Fiction games. Author Michael Taylor writes:
As for a basic run down of the rules, SNAFU is aimed at 15mm games of about platoon level (each side controls a platoon sized force plus support units) from the modern era into science fiction. The basic unit is the fireteam, usually 4 figures strong but sometimes less or more. As commander of this force you are concerned with the performance of your fireteams as whole units, not of the individual members of each team (leave that work to your team leaders!). As such, units move and fight as one whole.
A key part of the game is stress. The battlefield is a frightening and chaotic place, and how your troops deal with the stress of combat will effect their performance. As units take fire they will accumulate stress points, which makes them more difficult to activate. Adding to the chaos is the random draw deck to determine the order of play each turn. You can never be sure how many units you will get to activate, or when you will activate them.
Angels and Bears Aircraft Rules
Angels and Bears is a set of free wargames rules for modern air and naval combat. It focuses on the superpowers of the 1980s. The download features all the rules, counters and templates needed to play this game of air and naval combat.
Steel Inferno Armored Warfare Rules
Steel Inferno is a set of free wargames rules for modern armored warfare. The authors also provides statistics for some of Games Workshop’s Epic scale Warhammer 40k rules.
PZ8 1975 – 2010
A part of the comprehensive PZ8 series, PZ8 1975 – 2010 is a two page set of free wargames rules for 6mm figures.