A cooperative game in which player work to unseal hidden Wells of Light to prevent the shadow demon Xulthûl from overrunning the Realm of Aethos. The Wells are located in strongholds defended by powerful Guardians. If the players can find and unseal all the remaining Light Wells, they prevent Xulthûl from returning and win the game. If Xulthûl’s Shadows, however, manage to defile a single Light Well, the Shadow Lord will enter the Realm and the players must defeat Xulthûl in battle to save the Realm. Action system; random creature creation; different player powers; true cooperation.