Darts is game where a person aims at a dartboard and attempts to hit a specific section of it. It is a good test of hand-eye-coordination.
In 2371, Miles O'Brien and Julian Bashir began playing darts in a cargo bay on Deep Space 9. O'Brien later pursuaded Quark to allow him to play darts in Quark's. (DS9 episodes: "Prophet Motive", "Visionary")
The crew of the USS LaSalle had a dartboard aboard in the 2370s. Esteban Lopez challenged O'Brien to a game in 2372. Although Lopez played a good game, O'Brien defeated him. O'Brien did not ask for latinum, as he felt the challenge was payment enough. (DS9 novel: Saratoga)
Bashir and O'Brien introduced Worf to the game when he came aboard the station to investigate the Klingon fleet. Worf threw the dart, which imbedded itself deeply into the board. (DS9 episode: "The Way of the Warrior")
Julian Bashir was extremely adept at the game thanks to his genetically enhanced nature. After his secret was revealed, he began to play more normally. (DS9 episodes: "Doctor Bashir, I Presume", "Change of Heart")
Several weeks later, while Bashir was treating an injury O'Brien had sustained during the Battle of Cardassia, O'Brien told him he would miss their games when he left DS9 for Earth. (DS9 episode: "What You Leave Behind")