Warhammer Napoleonics is a set of stat lines and modifications for using the basic Warhammer Rules for the Napoleonic period.
Rules: Napoleonics
Captains Bold Frigate Rules
Captains Bold is a free print-and-play game for the age of sail. It focuses on duels between frigates.
Bugle and Shako Quick Play Napoleonic Skirmish Rules
Bugle and Shako are a set of free wargames rules for quick playing Napoleonic askirmish games.
Men O’ War Napoleonic Sail Rules
Men O’ War is a set of free wargames rules for Napoleonic sail. The rules are aimed at small actions, with one or two ships per player.
One Page Napoleonic Rules
Land of the Lead has a set of one-page Napoleonics Rules. They’re designed for play with a “reinforced division” per side. Scroll down to the bottom of the page to find them.