The Realm of Chaos Blog has a post on an old school (1988) Warhammer Fantasy Skirmish game
skirmish
Into The Darkness Skirmish Rules
Into the Darkness is a set of simple free wargames rules for skirmishes.
The author writes:
Into The Darknessis a tabletop war-gamefor two players. It is played on a 4×4 board, with each player alternating taking turns. Each player controls one (1) team, which may comprise as few as three but as many as nine models. Each model is given three points with which to purchase gear, though points may be gained with experience.
Goodbyeee! WWI Skirmish Rules
Goodbyeee! is a set of free wargames rules for Great War skirmish actions.
Sulphur Post-Apocalyptic Battle
Sulphur is a set of free wargames rules for post-apocalyptic skirmishes. There’s an accompanying 28mm line of figures.
Early 19th Century Wargames Rules
The prolific Tyneside Wargames Club has produced a set of free wargames rules for early 19th Century Skirmishes.