The Xuanwu (pronounced "shuan-woo") Gate Incident refers to an actual Chinese palace coup for the throne in the year 626 at the height of the Tang Dynasty. Li Shimin, the second son of Emperor Gaozu, planned an ambush at Xuanmu Gate leading to the Palace City and assassinated two of his brothers who were in a fierce competition with him for the throne. A few days after this coup, Li Shimin was made the crown prince. His father abdicated two months later, and Li Shimin became Emperor Taizong. The Xuanwu Gate Incident is a secret identity deduction game. Each player is dealt a character card that is secret to other players. On a player's turn, they may examine one of the two cards placed facedown in the center of the table. They may choose to swap the card with their own card, or with any other players' card, or keep it where it is. After all players have had a chance to examine one card, there will be voting to determine whether the current round comes to a showdown; if so, all cards are revealed and the winning team is determined.