Tough Men With Iron Balls is a set of free wargames rules for fighting 7 Years War and Napoleonic Naval Battles.
rules
Napoleonic Squares Rules
Napoleonic Squares is a set of free wargames rules for the Napoleonic Era from Steve’s Painting Shed.
Alien Invasion Rules
Matakishi has a set of free skirmish rules called “Alien Invasion”. The author writes:
This is a skirmish level game designed to be played by four to six players in about an hour and a half. Each player will control a competing faction with personal victory conditions to achieve based on the scenario chosen. Not all victory conditions are mutually exclusive so alliances and diplomacy have their place.
The game is ostensibly set in a fictional present day but this is not a requirement. Many of the factions are drawn from popular culture and new factions can be added very easily simply by quantifying a small number of variables.
The game requires minimal measuring, no charts and a lot of six sided dice. The rules will be memorised by a player by their second action and everyone can then concentrate on having fun.
The Wire World War I Games Rules
The Wire by Jim Wallman is not exactly a set of miniatures rules. Rather, it is a set of umpired rules designed to provide the participants with the feel of command during the Great War. Wallman writes:
This is the combat resolution system for a command post game about commanding brigades and divisions in WW1, particularly focussed on 1916. The rules are intended to be run in real time, and by umpires, who then write messages to the HQ players in the form they would have been historically, and subject to the delays and inaccuracies that would have existed at the time. The players never see the rules at all, and must work from a map (ideally in a smelly cellar by the light of a flickering oil lantern while umpires chuck buckets of earth at then).