Format
Each season was divided into two episodes, airing in consecutive weeks. The first season was divided into six episodes, with three chances to find the X-Man. The second and third season was divided into four episodes, with two chances. As of the fourth season, challengers only had one chance (two episodes) to find the X-Man. The various celebrities were divided into two teams, with one led by Kang Ho-dong (Kang Team) and the second by the other main MC (initially Kim Jae-dong, then Gong Hyung-jin, then Park Kyung-lim, then finally Lee Hyuk-jae). Yu Jae-suk served as the show's mediator and main MC. At the start of each episode, one celebrity would be chosen by the producer to be the X-Man, whose main mission was to disrupt teamwork in his or her team and purposely throw challenges while keeping his or her identity a secret. Winning teams of each mission would be awarded ₩1 million.
After all the missions, the guests then voted on who they think is the X-Man. The celebrity participant who was chosen was then digitally "fingerprinted" to see if the others chose correctly. If the others chose correctly, any money earned by the teams was donated to charity, under the names of the various guests. If they failed to find the X-Man, the X-Man was considered to have succeeded and the money donated to charity was given under the X-Man's name.
Read more about this topic: X-Man (TV Series)