The battle arena was a large room aboard the USS Phoenix-X, a renovated Klingon Combat Practice Room, where much of the crew practiced and competed in physical combat. Those people who were familliar the Phoenix-X were usually somehow privy to knowledge of this arena and its popularity. (Star Trek: Phoenix-X)
In one match-type, two opponents would usually be surrounded by a hovering purple or blue laser marker line that acted as their fighting-area boundary. When an opponent was knocked passed the marker-line, the other would be claimed the victor.
The battle arena, foremost, served as an area for the Klingon-half of the crew to let their need for real combat go free and to mediate their frustrations with living aboard a Starfleet vessel. It secondly served as an interest for the rest of the crew to indulge in hand-to-hand combat. The martial-arts became an ongoing venture with most of the crew. In 2381, a fighting tournament was held between the crew within the Arena, seeing Lieutenant Elly as the winner. ("Phoenix Restoration", "King of the Iron Fist Tournament")
In times of great pressure, the Captain would more than often book time and use the arena to meditate. ("Jumpers, Parts I & II", "Destiny's Revenge, Part I", "The Shadow Maneuvers", "New Beginnings") Lieutenant Kayl had been known to go to the arena for meditation as well, due to her telepathic abilities. ("Destiny's Revenge, Parts II & III")
- Star Trek: Phoenix-X
- Star Trek: Immortal Coil - when Captain Sith visits Qo'noS
- Star Trek: Resurrections