Voice Credits:

• This episode was a landmark in that it crossed over into Larry Niven's Known Space universe.
• As related by Larry Niven in his 1991 book Playgrounds of the Mind, in 1973, Dorothy C. Fontana asked Niven to write an episode of the animated STAR TREK series. His first story treatment involved quantum black holes and the Outsiders - a very alien species which were built like a black cat-o'-nine-tails using photoelectric metabolism. Fontana advised him that the story wouldn't work. His second attempt proved to be "too bloody." While at Gene Roddenberry's house one afternoon, Gene suggested that Larry Niven rewrite his short story "The Soft Weapon" which had been reprinted in 1968 in Neutron Star a collection of Larry Niven's stories. This third attempt became the finished episode "The Slaver Weapon." Interestingly, Niven's first idea which involved quantum black holes, formed the basis for his story "The Borderland of Sol" which was first published in the January 1975 issue of Analog magazine (see left). "The Borderland of Sol" was such an excellent story, that it won the 1976 Hugo award (pictured right) for best novelette.
• This was the only episode of the original and animated series in which neither the Enterprise nor Captain Kirk appeared. Only series regulars Spock, Sulu and Uhura appeared in this episode.
• Rarely, if ever, in a Saturday morning cartoon show are people or even animals seriously harmed or killed. However, in this episode, when the Slaver weapon self destructs, the explosion kills four of the Kzinti. Once again, this was not just another kids' show.
• The Kzinti police cruiser ship seen in this episode was pink in color. When asked why the fearsome Kzinti warriors would be flying around in a pink ship, series director Hal Sutherland (pictured) replied that he hadn't realized that the production department had made the ship pink since he was color blind.
• The Slaver device was an espionage agent's weapon which could change shape to become several different tools such as a laser, a computer, a telescope and an immensely powerful total-conversion beam.
• Life-support belts played an important part in this episode. Spock, Sulu and Uhura used the belts to allow them to venture onto a small icy, airless planetoid. The life-support belts were used on the animated series as a cost cutting device. In order to be able to produce an animated half-hour series in the 1970's with a very limited budget, the production company had to take as many short cuts as possible. These include limiting action to a minimum and recycling sequences of drawings. So, rather than draw a new sequence of Kirk and Spock walking with spacesuits on, they would reuse a sequence of the two walking and would just draw on the belts and add a glowing outline around their bodies.
• There is a page in this site that focuses on the Long Range Shuttlecraft Copernicus that was used by Spock, Sulu and Uhura in this episode.
• There is also page devoted to the Traitor's Claw, the Kzinti ship that featured prominently in this episode.

• Kzin hand phasers were shown in this episode, and they looked just like Federation phasers, but were red in color.

• The Slavers and their empire, which were mentioned in this episode and in the original short story, first appeared in the 1965 novella "World of Ptavvs" by Larry Niven which was published in the March 1965 issue of Worlds of Tomorrow magazine. The actual name of the Slaver species, which was not mentioned in the animated episode, was the Thrint.
• There was a visual error in this episode: when the back doors of the Copernicus were shown openning from behind, they disappeared impossibly on each side of the ship. (Picture showing this error, 36KB jpeg).
• In another visual error in this episode: Spock's life-support belt spontaneously vanished in one scene.
• "The Slaver Weapon" was novelized by Alan Dean Foster in Star Trek Log Ten published by Ballantine Books in January 1978, bringing Larry Niven's short story full circle. The entire book was devoted to this one episode.