Set in the Chaotic universe and packed with 25 miniatures and 3D components, Underworld Battle has the players taking the role of OverWorld heroes fighting monsters as they advancing through the UnderWorld City Battle Arena. The game ends in a climatic battle against Chaor, the Underworld's ruler. Player order is randomized at the start of each turn by shaking Chaor's Staff of Chaos, which contains four different coloured balls that correspond to the player's miniatures. Players have three action points per turn to move or attack in any combination. After all the players move, the denizens of the Underworld City act, and may attack the players. Players gain points for collecting treasure, battle gear and defeating monsters, with the one to defeat Chaor receiving a substantial bonus. The player with the most points after Chaor is defeated is the winner. This is a rebadged and re-implemented version of Waddington Games Dark World fantasy game.