As Netflix was targeting the work for a global audience, the visuals were emphasized and some of the rules of the children's games were simplified to avoid potential issues with the language barrier.[44] The colorful sets and costumes were designed to look like a fantasy world. The players and soldiers each wear a distinctive color, to reduce the sense of individuality and emphasize the difference between the two groups.[41] The green tracksuits worn by the players were inspired by 1970s athletic wear, known as trainingbok (Korean: 트레이닝복).[84] The maze-like corridors and stairs drew inspiration from the 4-dimensional stair drawings of M. C. Escher including Relativity. Production designer Chae Kyoung-sun said these seemingly infinite stairways represented "a form of bondage for the contestants".[85] The complex network of tunnels between the arena, the dorm, and the administrative office was inspired by ant colonies.[41]