Genius gamer siblings (plus being NEET & hikikomori) Sora and Shiro are known as the undefeatable “__” (blank). Their talents and skills are so good they are considered as urban legend. One day, a young boy named Teto appears before them, claiming to be the “God” of another dimension where Sora and Shiro are summoned to, in which no violence is allowed and everything is decided by a game. Of the 16 different races residing in this world, “Humanity” is the weakest. After having the vast majority of their lands captured by the other races and being driven to the brink of extinction, Sora and Shiro challenge these one-of-a-kind battles of the intellectual powers in order to save Humanity.
No Game No Life features a pair of gamer protagonists known collectively as "Blank" (a combination of their two names, written in their native language Sora and Shiro: 空白) who are transported to another world by the god of games. (Tet) On this world where violence is forbidden, populated by magical creatures, all matters are settled through games and humanity is on the brink of extinction. Using their combined intellect, questionable morals and considerable guile, it is up to these siblings to swindle their way to the top in a series of increasingly intriguing and deceptively deadly games.

[Source: Anime News Network]