Playing an unreleased computer game
repeatedly in order to find its bugs
so that the programmers
can fix them. Involves long hours at tedious, mind-numbingly repetitive tasks for little or no pay.
The benefits of being a playtester are mostly nonphysical: The prestige of working for a game company, being able to say you play games for a living, having your name in the manual of a popular game. If you playtest long enough, you may be invited by your company to become a game developer.