Siege was a popular game inside the Ether. It served much the same purpose as many other role-playing games: to entertain the users as a quest-based RPG with varying character classes, power-ups, abilities, weapons, tasks, and typical game progression elements. Within the game, like most Ether functions, one could take on any appearance they desired for their gaming avatar. Very little if any restrictions were put in place regarding appearances, ranging from a warrior rabbit with a massive sword, to a samurai warrior or steampunk renegade.
Before and after the attack on New York, it was a pastime for Julian Chase and Miguel Garza to play the game while off-duty. Cammie was considered by the other members of her team to be addicted to the extremely immersive game. It was to the point of staging an intervention for her when they felt she was disengaging from reality. Other notable users included Kazu Iida's father, Toshiro Iida.
Siege was the host of the early stage gen:LOCK entity known as Sycorax; until its deletion by Cammie during the gen:LOCK team's stay in the Japanese Polity to reduce Sycorax's processing power. What remained of it was repurposed by Cammie to serve as a cyberspace hub for Chase to unwind in his downtime due to the loss of what remained of his body. In this capacity, the combat elements of the game were removed to give Chase at least one place in the world where he did not have to be a soldier.