Bluff
A bluff was a deception tactic built on an empty boast. It was a common tactic in games like poker, but also had applications in real life. One such example of a bluff applied in real life was the Corbomite Maneuver. ()

H-bombs were built on 20th century Earth as a bluff, never intended to be really used. Upon encountering the planet killer in 2267, James T. Kirk theorized that it served a similar goal. Upon being accused of bluffing, Spock later claimed that Vulcans never bluffed. ()

In 2268, while Kirk and a Klingon crew under the command of Kang were fighting under the influence of the Beta XII-A entity, Kirk threatened to kill Kang's wife. However, Kang called his bluff. ()

In 2269, while the  and the  were trapped in Elysia, the S-2 graf unit of the Klothos suffered damage, but its captain, Kor, tried to bluff Kirk by pretending they were doing fine. ()

In 2270, the computer of the  fooled the Romulans
with a giant , prompting Leonard McCoy to remark that it was an effective bluff. ()

During the V'ger crisis in the 2270s, Kirk tried to bluff the probe, but to no avail. ()

When the  was being held hostage by Nagilum in 2365, Jean-Luc Picard responded by initiating the ship's auto-destruct. Nagilum ultimately responded by releasing the ship. ()

The same year, Worf claimed that Klingons never bluffed, but Geordi La Forge believed this to be a bluff itself. ()

Data compared Picard's refusal to retreat to the tactic of bluffing, describing, "In the game of poker, there is a moment when a player must decide if an opponent is being deceptive or actually holds a winning hand. This decision is based not only on the odds, but also on an appraisal of the man. Is he bluffing or does he have the cards?" ()

In 2368, the Enterprise-D encountered a Tamarian ship that behaved in a way they did not understand. One theory offered by William T. Riker was that they were bluffing. ()

During a discussion about Romulan strategy between Mot and Jean-Luc Picard later that year, Mot opined that there's a time when you want to call a Romulan's bluff and there's a time when you don't. Picard countered that one did not always have the luxury. ()

On their way to Cardassia IV in 2370, Kira Nerys and Miles O'Brien managed to bluff a Cardassian Navigational control post which had managed to detect them. ()

Benjamin Sisko, according to Jadzia Dax that year, was a terrible bluffer, at least in poker. She claimed that she had spent two lifetimes trying to improve his bluffing, but to no avail. ()

After traveling back in time to 1947, Quark mentioned root beer to Lieutenant General Denning as an example of his knowledge of Human culture. This was a bluff to cover his lack of knowledge. ()

In 2369, after Kira Nerys had successfully tried to bluff Gul Jasad into thinking Deep Space 9 could put up a good fight, Chief O'Brien asked Kira to remind him never to play Roladan Wild Draw with her. ()

In 2375, during the Dominion War, a conflict emerged between Bajor and the Romulan Star Empire concerning the arming of a Romulan hospital on Derna. Colonel Kira attempted a daring bluff, taking a fleet of Bajoran impulse ships to prevent an approaching group of warbirds from reaching the moon, even though they would not be a match for even one warbird. Kira hoped that the Romulans would not dare endanger their alliance with the Federation by firing on the ships. Ultimately it was not the Romulans, but Starfleet Admiral William Ross who blinked, with Ross threatening to remove the hospital using Federation forces. ()

Kathryn Janeway was also an occasional bluffer. In 2375, Janeway tried to bluff Y'Sek, a bounty hunter, but he called her bluff. Confronted with an electromagnetic lifeform in 2376, she successfully bluffed the creature by creating a situation where, if it did not cooperate, they both would die. ()

In the Enterprise-D senior staff poker game
For years, the senior staff of the Enterprise-D held a weekly poker game every Tuesday evening. As a result, the participants became very good in bluffing each other and calling each other's bluffs.

During a 2367 game, William T. Riker remarked that Data was getting harder and harder to bluff. ()

During a 2368 game, Riker and Beverly Crusher discussed bluffing as Crusher called Riker's bluff only for Riker to predict that Crusher was going to call his bluff again a little bit later, each basing their correct calling of the other one's  bluff on "just a feeling". Crusher joked that when Riker bluffed, he raised his left eyebrow in a particular way. ()

Thomas Riker, a transporter duplicate of William T. Riker, joined a game held in 2369. When Thomas raised 100, William commented that he had practiced too long in the mirror to be fooled by his face, and he was bluffing. Thomas said that it ought to be clear to him by now that the two of them played things a little differently, but when he raised 300 more, William said that he knew he was bluffing and chose to call and raise everything left, forcing Thomas to reveal that he was, in fact, bluffing. ()

According to Worf, Deanna Troi never bluffed during poker, but in 2370 she implied that she might just have hid her bluffs well. ()

In 2370, the junior officers and the senior officers played a poker game against each other and mirrored each others moves. As the game ended Riker and Lavelle were caught bluffing by the other members of the staff. (TNG: "Lower Decks")

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