(covers information from several alternate timelines)
Parrises squares, or parisses squares, was a vigorous and rather violent athletic game played by people from many worlds and ages during the 24th century. Its popularity among youth was a concern for parents. (VOY: "Real Life") Players were called "parrises players". (VOY: "The Fight")
The game was played on a court, and involved two teams of four players. Substitutions were possible, which allowed teams to rotate active and resting teammates. Some players, such as Commander William T. Riker, disliked the practice, feeling that doing so created a disruptive loss of a team's "rhythm". (TNG: "11001001")
When playing parrises squares, players wore padded uniforms and used a piece of equipment called an ion mallet. The game also involved a ramp, and if players were not careful, they could fall off and injure themselves. (TNG: "Future Imperfect")
Raymond Marr, a colonist on Omicron Theta, played parrises squares with a group of his schoolmates. He started when he was very young but was gifted and even won a championship emblem in the game. (TNG: "Silicon Avatar")
The Starfleet Academy team faced the Minsk team in the parrises squares Championship Finals of 2324. It came as a big surprise when Starfleet Academy won, as the Minsk team was favored. Starfleet cadets threw a celebratory party that wreaked havoc on the academy grounds and took the head groundskeeper at Starfleet Academy, Boothby three weeks to repair. (TNG: "The First Duty")
While healing a deep cut on William Riker's face, which he acquired from Data's cat, Spot, Doctor Crusher admonished him, giving an order to "Stop playing parrises squares as if you're 21!" She continued dispensing advice: "One of these days, you're gonna fall and break your neck, and I'm not gonna be able to heal that as easily." (TNG: "Timescape")
In 2373, The Doctor created a holographic family to help him better understand and empathize with his patients, and his daughter, Belle, was on her school's parrises squares team. This worried her parents, especially The Doctor, for parrises squares was a potentially dangerous game – even more so for Belle, who played in a league of children older than her. Their concern proved prescient and justified as she later died from injuries sustained during a competition. (VOY: "Real Life")
According to Lieutenant Tom Paris, Ensign Freddy Bristow played "a mean set of Parrises Squares." Lieutenant B'Elanna Torres, however, was not impressed, stating that she had played one game with him and whipped him. (VOY: "The Swarm")
In the fictional future created by Barash for William Riker, Barash's avatar Jean-Luc Riker broke his wrist playing Parrises Squares. The elder Riker was displeased that Jean-Luc was playing Parrises Squares at his age, saying he could have broken his neck, but Dr. Crusher politely pointed out to him that Will was even younger than Jean-Luc when he began playing. (TNG: "Future Imperfect")
- See: List of athletes
The video game Star Trek: The Next Generation - Echoes from the Past gives an alternative spelling to the game's name as "Parisi Squares".
The second issue of the Star Trek: Spock: Reflections comic reveals parrises squares was played as early as the 23rd century. In 2253, Lieutenant José Tyler invited Spock to join in a game of parrises squares which was being held in the USS Enterprise's rec room with some of the other crew members, but Spock declined the offer.
In the first issue of IDW Publishing's Star Trek: Starfleet Academy series set in the alternate reality, a Tellarite named Trumble played parrises squares on the Academy's team, the Fighting Phoenixes before becoming an Academy instructor.