Synopsis : There was an urban legend that there was a legendary, undefeated gamer called 『 』, but in reality he was just a NEET brother and sister called 空 (Sora) and 白 (Shiro). These hikikomori siblings who both refer to the real world as a worthless "Kuso Game" are one day summoned to a different world by a boy calling himself "God". In this world, war is prohibited by God and everything is instead decided by a game...that's right, even country borders. Can the two NEET brother and sister save the last of the human race Imanity , which only has one city left? "Now...let the game begin!"
Before the game start both party must say "Acciente" as the signal to start the game under the ten oaths : 【1】 All bloodshed, war, and pillage is forbidden throughout the world. 【2】 All disputes are to be resolved through the outcome of games. 【3】 In games, wagers will be made on what both parties decide to be of equal value. 【4】 Unless contrary to "Three", the game content and the things wagered do not matter. 【5】 The challenged party has the right to decide the contents of the game 【6】 "As per the Oath", the wager will be unconditionally adhered to. 【7】 All matters for group conflicts will be decided by a representative. 【8】 If cheating is detected during a game, it will be regarded as a defeat. 【9】 The above rules are unconditionally everlasting, upheld in the name of God. 【10】 Everyone should get along while playing games .
Despite rules prohibiting violence, there is still a shooting game, a chess/war and a game which ended with a super nova. Also, if a second season is created, the novels would imply that the violence will get more intense.