A Starfleet Academy command simulation in which cadets attempt to rescue a stranded ship, designed so that it cannot be won and testing character in the face of defeat.
The Kobayashi Maru is a training simulation used by Starfleet Academy to evaluate command cadets. The cadet receives a distress call from the civilian fuel carrier Kobayashi Maru, stranded inside the Klingon Neutral Zone. Entering the zone to attempt a rescue triggers an overwhelming Klingon attack, while leaving the ship means abandoning its crew. The scenario is designed so that no choice leads to victory.
It is introduced at the opening of Star Trek II: The Wrath of Khan, where Saavik's bridge crew is destroyed in the simulation. James T. Kirk later reveals that he is the only cadet ever to beat it, having secretly reprogrammed the simulation, and was commended for original thinking. The 2009 film shows the Kelvin timeline Kirk doing the same and facing a disciplinary hearing, and Prodigy devotes an episode to Dal R'El repeatedly failing a holodeck version.
The test has become a byword, both inside and outside the franchise, for a no-win situation. It captures Kirk's defining refusal to accept that defeat is inevitable.