BLD provides free shipping and returns for systems that do not meet BLD engine performance standards—within 10% +/- of frames per second (FPS) under stable, unaltered conditions(no overclocked or altered hardware settings). Our testing of each game's FPS is conducted with Fraps(linked here: https://www.fraps.com/) or with an in-game benchmark if provided( Example photo provided from Shadow of the Tomb Raider)