The world is dying. The country of Solum are surrounded by poisonous fog. This fog devours everything on its way, and is slowly moving towards the few remaining towns and villages, about to consume the rest of humanity. The main religion of this world, Aeque, preaches that this is the will of God, and that the human beings should not resist and allow themselves to extinct. But an underground rebel movement is trying to dispel the fog with a magical structure called Gate of Eternity. Spero, the young protagonist of the game, must find his place amidst the conflict between the Empire he serves and the rebels.
Stella Deus is a tactical role-playing game. You command your units by moving them around the isometric battle view. Each action - whether movement, physical attack, or magic spell - requires action points (AP). After the battles, your characters gain levels and get new abilities. Outside of battle, you can tackle the huge optional dungeon, Catacomb of Trials, and access towns via the menu. In towns you can fuse items to obtain more powerful ones, and receive side quests which mostly involve going to a certain place on the map and participating in a battle there.