H.G. Wells' Little Orc Wars

From the Quick-Play Rules:

"H.G. Wells' Little Orc Wars is a miniatures game based on the rules and concepts published by the genius science fiction author nearly a century ago. It is, in fact, one of the most flexible, innovative, and fast-paced miniatures rule systems for use with fantasy miniatures and models ever created. Indeed, a primary feature of this game is that it can be played with virtually any miniatures, setting it apart from the vast majority of fantasy miniatures games, which demand that only their branded products be used to play.

Other highlights of the complete book include advanced melee rules that expand upon the basic ones created by Wells that are presented here: guidlines on building props and models; examples of play depicting some of the best wargaming models currently available, including those by the Miniature Building Authority, Armocast, Fantascene, Dwarven Forge, and Flying Tricycle and action-oriented images of miniatures in play."

Little Orc Wars and its predecessor, Little Wars from H.G. Wells, provide a simple set of rules for wargaming using miniatures (or anything else you can find to represent troops). Little Orc Wars focuses on fantasy and the basic rules for moving troops, melee, ranged combat, terrain effects, etc.--although modern rules are more complex, these rules capture the feel of combat with very little effort or time.