|USS Enterprise-D senior staff play.|
|Data playing on the holodeck.|
|USS Enterprise-D junior officers play.|
|A few Voyager senior staff members play a game aboard the Delta Flyer|
Poker was a traditional Earth card game of chance and skill.
The game had many variations but all forms of poker were games of incomplete information in which the players wagered on the strength of their cards relative to those of the other players, at least some of whose cards are hidden from the other players at the table.
An alert player could increase their chances of winning by observing opponents and judging by their expressions and actions the value of the cards they held. Conversely, part of the game was for players to disguise that value, called "bluffing" and/or provide as little information for their opponents as possible, such as a strictly emotionless facial expressions, called a "poker face."
While infected with a silicon-based virus, Hoshi Sato confessed to Charles Tucker that she had been discharged for breaking her CO's arm over a dispute about organizing a weekend-poker game for new recruits. (ENT: "Observer Effect")
The senior staff of the USS Enterprise-D held a weekly poker game every Tuesday evening. Typically five-card stud was played. Most of them were frequent participants with the exception of Captain Picard. He had a standing invitation for several years, but never accepted it until after his encounter with the anti-time anomaly in the Devron system. (TNG: "Cause and Effect", "All Good Things...")
When he was first introduced to the game in 2365, Data believed that the game could be played with a simple mathematical strategy, but he did not yet understand the practice of bluffing, which greatly complicated matters.(TNG: "The Measure Of A Man") Over time, Data grew to consider poker to be an interesting forum for the study of Human nature. He designed a holodeck program in which he played poker with three of Earth's greatest scientists: Albert Einstein, Isaac Newton, and Stephen Hawking. (TNG: "Descent") In addition, his inability to have emotions naturally gave him the ultimate poker face which enhanced his already considerable skill at the game. That skill proved invaluable when he was flung back in time to the 1890s San Francisco and raised needed funds by joining a poker game and apparently cleaning his opponents out of their money and even some clothing. (TNG: "Time's Arrow")
In 2368 Deanna Troi experienced memories about a poker evening with William Riker. Due to the telepathic memory invasion performed by the Ullian Jev she had no good feelings about this event. In her experienced memories several poker chips fell on the ground and Riker/ Jev then raped her. (TNG: "Violations")
During one game in 2368, Deanna Troi suggested that they play a "Federation Day" variant of the game, where twos, sixes, and aces were wild cards (corresponding to the Federation's founding year of 2161). Worf commented that the large number of wild cards was a "Woman's Game" because it "supports a weak hand". (TNG: "The Outcast")
Although the games on the Enterprise-D were usually played for common clay chips, one game between William T. Riker, Worf, Geordi La Forge, and Beverly Crusher was wagered on an unconventional stake: if Beverly won, all of the men would shave their beards, and if any of the men won, Beverly would dye her hair brown. The game was unfortunately not finished. (TNG: "The Quality of Life")
On the Enterprise-D, some of the junior officers held a weekly poker night as well. Among the regular players were Sam Lavelle, Taurik, Sito Jaxa, Alyssa Ogawa, and Ben, a waiter in Ten Forward. (TNG: "Lower Decks")
Admiral William Ross also played the game. After Colonel Kira Nerys was successful in removing Romulan plasma torpedo launchers from Derna, he told her to remind him "never to play poker with you". (DS9: "Shadows and Symbols")
Apparently, during long away missions, several members of Voyager's crew also played Poker, even at one point teaching the game to Neelix, who was seemingly less than proficient at the game. At one point, Chakotay, Tom Paris, Harry Kim and Neelix played for a morning off instead of chips. Unfortunately, before Tom could reveal his winning hand, a Borg cube appeared and interrupted the game. (VOY: "Collective")
Ronald D. Moore commented that it was a running joke among the writers that Worf could never win at poker. (AOL chat, 1997) However, this joke started after season 2, since the Klingon totally dominated the game seen in "The Emissary".
Marina Sirtis has noted that her character, Deanna Troi, should not have been allowed to play poker, due to her empathic abilities.