Portrayed by Denise Crosby, Yar is chief of security aboard the Starfleet starship USS Enterprise-D and carries the rank of lieutenant.

Yar was described as a forerunner to other strong women in science fiction, such as Kara Thrace from the 2004 version of Battlestar Galactica, while providing a step between the appearances of female characters on The Original Series to the command positions they have on Star Trek: Deep Space Nine and Voyager.

[2] The producers considered Jenette Goldstein, who had played Vasquez, for the role, but writer Dorothy Fontana pointed out that the actress "is not Latina.

By the time that the writers' and directors' guide for the series was published, dated March 23, 1987, the character was named Natasha "Tasha" Yar.

[4] Her surname was suggested by Robert Lewin, drawing inspiration from the Babi Yar atrocities in Ukraine during the Second World War.

She was planned to have a friendship with teenager Wesley Crusher, and was described in the guide as "treat[ing] this boy like the most wonderful person imaginable.

"[5] In April 1987, Lianne Langland, Julia Nickson, Rosalind Chao, Leah Ayres, and Bunty Bailey were each listed as being in contention for the role.

[7] The writers and directors guide described Yar as having a muscular but very feminine body type, and being sufficiently athletic to defeat most other crew members in martial arts.

Shortly after Ishara's birth, the girls' parents were killed and they were taken in by other people; however, they were subsequently abandoned and Tasha was required to look after her sister on her own.

[16] Yar appeared for the first time in the pilot episode of Star Trek: The Next Generation as the Security and Tactical Officer on board the USS Enterprise-D.

[19] In "Code of Honor" Yar is abducted by Lutan, the leader of the planet Ligon II, after she demonstrates her combat skills on the holodeck.

[21] Yar forms part of the away team that beams down to Vagra II to rescue Deanna Troi from a crashed shuttlecraft in "Skin of Evil".

Based on that advice, Yar transfers to the Enterprise-C and returns with it to two decades into the past, and its expected destruction at the hands of the Romulans while defending the Klingon outpost Narendra III.

She needs to be convinced by Picard to put the ship in danger in order to destroy the temporal anti-time anomaly that threatens to prevent life from evolving on Earth.

[28] Yar appeared for a brief but prominent moment of Picard, Season 3, episode 8 "Surrender" as a visual representation of Commander Data's memory.

Captain Carol Freeman of the USS Cerritos mentions that the Enterprise crossed universes "while battling some evil clones of Tasha Yar, or something," but she can't remember the exact details.

[30] A Den of Geek article by Martin Anderson also about women in Star Trek described the character as a predecessor to Kara "Starbuck" Thrace in the 2004 re-imagining of Battlestar Galactica.

He noted specifically that women appeared in command positions more regularly as main and supporting characters, and were portrayed as more assertive and combative, with leading roles in action sequences.

[34] In the book Science Fiction Audiences: Watching Doctor Who and Star Trek, the authors describe her as "an obvious bisexual",[35] but that "she should be a lesbian".

[35] The authors of the book Deep Space and Sacred Time: Star Trek in the American Mythos also thought that having Data and Yar consummate sexually was a means to state early on in the series the heterosexuality of the two most androgynous characters in the show.

Keith DeCandido called it "pointless", but thought that it was no worse than the deaths of other security officer "redshirts" throughout the history of Star Trek.