Alienstar offers a set of World War II rules for battalion to Corps level games.
rules
Roses Of The North Wars of the Roses Skirmish Game
Roses of the North is a set of free wargames rules for Wars of the Roses skirmishes.
Under The Shade Of The Trees ACW Rules
Under The Shade Of The Trees is a set of free wargames rules for the American Civil War. They’re designed as “fast play” and suggest using standard Johnny Reb or Fire and Fury basing.
English Civil War – One Hour Wargame
English Civil War is a modification of the Horse & Musket/Pike & Shot rules in Neil Thomas’s ‘One Hour Wargames.’
Great Northern War – One Hour Wargames
Alan Saunders offers Great Northern War, a set of free wargames rules that he describes as:
A heavily modified version of the Horse & Musket/Pike & Shot rules in Neil Thomas’s ‘One Hour Wargames’ specifically for use with the Great Northern War.