Gears of War: E-Day features a new multiplayer mode called Horde Siege, where 12 players are divided into three squads with unique objectives on the same map. The gameplay includes large-scale events like Boss Invasions that encourage cooperation among squads. A preview session showcased the 'Blitz' variation on the Golden Quarter map, using high-end PC specifications. Players who pre-order the game will access an open beta from August 6-10, which will include one Horde Siege map and a level cap of 10. The beta will also feature two Versus modes and two maps, while the full game will launch on October 6 with additional content. The Premium Edition offers five days of early access starting October 1.