unplayable
Too damaged or difficult to be played or used.
When something is unplayable, it cannot be played, either because it's in such bad condition that playing it is impossible, or because it's so difficult that even skilled people can't manage it.
A scratched DVD might be unplayable because the player can't read it anymore. A warped vinyl record becomes unplayable when the grooves are too damaged to produce sound. An old video game cartridge covered in dirt might be unplayable until someone cleans it carefully.
In sports, unplayable often describes conditions that make a game impossible or dangerous. A baseball field flooded with rain becomes unplayable. A tennis ball that lands in thick bushes might be declared unplayable, meaning you can't reasonably hit it from where it lies.
The word also describes something so difficult that it defeats even experts. A music piece with impossible fingering might be considered unplayable on piano. In video games, a level with no solution or unfair difficulty gets called unplayable by frustrated players. A serve in tennis that's so fast and well-placed that the opponent can't possibly return it is an unplayable serve.
The opposite of unplayable is playable: working properly and possible to use or complete.