A no-win situation caused by a set of rules that can only be won by changing the rules, in effect, cheating. This term comes from the name of a small ship in distress in a scenario shown in a Star Trek movie. According to the film, the scenario is featured in a training simulator for students attempting to become ship's captains. They receive a distress signal from the Kobayashi Maru and can either attempt to rescue it and be destroyed by enemy forces or leave it and let it be destroyed. James T. Kirk, according to the film, is the only person to have won the scenario--by reprogramming the simulator. Kobayashi Maru, loosely translated, means "Little wooden ship."
Someone experiencing a Kobayashi Maru can be said to be between a rock and a hard place.