Checkmate is a world champion Quartex and MilCard player, and one of the most respected tacticians of the Circle. He is wheelchair-bound due to a degenerative illness, which would have killed him if his parents hadn't taken him to Kallipolis for treatment at a very young age. Because of this, he is a supporter of the Encircled Immortals, a patriot of the Circle, and a loyal member of the Technocracy.