Master Key (TV series)

The game starts with the 12 players trying to find 12 keys scattered around Master Village, one for each player, before proceeding to the Room of Fate and check if their respective key is one of the two Master Keys or not. Players will then be divided into two teams of 6 and compete in various Investigation Mission games in order to obtain clues about the Master Key owners. The audience also acts as Watchers and can vote for one of the players before each episode to allow the player to win a special benefit of obtaining additional clues about the Master Key owners. At the end of the episode, the players must vote for two names that they believe are the Master Key owners. Players who correctly vote for both Master Key owners will win the prize of 12 gold keys. The two Master Key Owners will have to avoid getting voted the most and must find each other in order to win the 12 gold keys prize. If none of the two scenarios happen, there will be no winners.[2]

The 12 players proceed directly to the Room of Fate where each of them picks one among 12 keys placed inside the room. Among the 12 keys, one is the Angel Master Key and another one is the Devil Master Key, the rest being the regular keys. Players will then be divided into two teams of 6 and compete in various Investigation Mission games in order to obtain clues about the Master Key owners, while each trying to individually win the votes from other players by claiming himself/herself as the Angel Master Key owner. The audience also acts as Watchers and can vote for one of the players before each episode to allow the player to win a special benefit of being able to cast 2 votes instead of 1 vote for the final voting. At the end of the episode, the players must vote for one name that they believe is the Angel Master Key owner. The prize is distributed according to one of the three possible results below:

• If the Angel Master Key owner is the most voted player, the prize is won by the owner of the Angel Master Key and all players who voted for him/her. The amount of gold keys won by each of them is the base prize number of gold keys multiplied by the number of votes received by the Angel Master Key, then are equally distributed among all winners.
• If the Devil Master Key owner is the most voted player, the prize is won by the owner of the Devil Master Key. The amount of the gold keys won is the base prize number of gold keys multiplied by the number of votes received by him/her.
• If one of the regular key owner is the most voted player, the prize is won by the most voted player. The amount of the gold keys won is the base prize number of gold keys added by the number of votes received by him/her.

The format is slightly changed on episode 8. Out of the 12 players, two players will be randomly assigned with the ability to cast extra votes at the final voting, one being able to cast 2 votes and another being able to cast 3 votes. The Devil Master Key owner will also gain an additional vote each time his/her team win an Investigation Mission game. The benefit for the Watchers' voting winner has also changed to a phone call with the Key Man, where the benefit winner can ask two questions and the Key Man will only answer yes or no.

A further change is implemented on episode 9 of which the number of Devil Master Key owners is increased to two and there is only a player randomly assigned with the ability to cast 3 votes. The benefit for the Watchers' voting winner changes to selecting a player and confirm whether that player is a Master Key owner or not, and is only known to the voting winner. At the end of the final voting, if one of the two Devil Master Key owners is the most voted player, the prize will be won by both Devil Master Key owners. The amount of the gold keys won is the base prize number of gold keys multiplied by the number of votes received by him/her, then is divided equally among both Devil Master Key owners.

The format underwent a major change. There are only 7 players and one Master Key. In the beginning, the players have to work together as a team to find Master Cars. Each Master Car has one mission and if the players complete it, they get a key and check whether it can open the box or not. If they find both keys to open the box they get 6 keys and only one of them is the Master Key and one player doesn't get a key. The players have to find boxes and try to open them with their own key and if they can open 2 or more boxes then their key is the Master Key and they can open the Master Box which has one golden key as a prize. The winner can be the owner of the Master Key or another player who steals the key.

At the beginning of the episode and after one mission, the 7 players have to choose one of the two choices, which are different. If they win the mission they get either one or two keys. If every player has one key, everyone has to open a box and choose between the two choices individually. If all members choose '7' everyone gets a golden key but if they choose '1' only one of them can win and the Master Key belongs to the players that chose '7'.

Lee Soo-geun was the MC while others formed three teams: Jun Hyun-moo and Mingyu were part of the white team, Kim Dong-jun and Ko Sung-hee of the yellow team, and Kim Jong-min and Jeong Se-woon of the green team. They played Olympic games and the team with the most points won.

The members have to escape by completing the missions and gaining the keys to open the box with the tickets for the bus to Seoul and they only have limited time. On the way to Seoul they have to complete missions at rest stations to get hints about the location of the Master Box.