In King Arthur: Legion IX, players engage in turn-based tactical combat while managing a party of 5-6 heroes, exploring the mythical land of Avalon. The game emphasizes deep tactical strategies, including cover usage, traps, and an overwatch system, requiring players to make thoughtful decisions in battle.

The storyline follows Gaius Julius Mento, a tribune of the undead Ninth Legion, as he navigates Avalon after being summoned by a demonic emperor. Players must confront various foes, including Pict tribes and Sir Mordred's knights, while deciding whether to embrace demonic power or restore their humanity.

King Arthur: Legion IX stands out with its unique blend of tactical RPG elements, character-centric gameplay, and a rich narrative that allows players to shape their hero's destiny through moral choices and city-building mechanics.