A QA tester's job is to play video games that are nearing completion to identify bugs, glitches, or other issues that break the game. They test to ensure the game works as intended and provide feedback on gameplay and areas for improvement. QA testing involves repeatedly playing games, including unfinished versions, to identify all possible issues and ensure the game is free of flaws before public release. It is a repetitive job but critical to the quality of the final product. Strong knowledge of games and persistent passion for playing are important for QA testers.