Chess was a board game for two players.
Before Day 1
Kim Bauer was a member of the school chess club at Santa Monica High School. In her second year at Santa Monica, Kim dropped out of all clubs except the chess club. Prior to her match with her father, Kim had recently finished reading a new chess book. Jack felt Kim had a talent for chess due to being a natural strategist. (Findings at CTU)
Jack and Kim Bauer were playing chess at approximately 12:03am of Day 1. About 11 hours later, after Jack found Kim and Teri, who was kidnapped, Kim claimed that she was only two moves away from checkmating him.