Codex Martialis is a heavily modified d20 System game, with a focus on martial combat and historical realism. The game can alternately be used in a modular fashion, replacing the combat system in another d20 System game.
Make a character with a real martial skillset that makes a difference when you fight. No more waiting for an opportunity to make one attack... move, defend, attack, and attack again all in the same round, without getting bogged down in charts or arithmetic, and without relying on miniatures. Chose your weapons based on your personal fighting strategy, emphasize attack, defense, grappling from a distance, or armor-piercing. Specialize in fighting close-in or far away, with missile weapons or melee.