It’s hard to believe that the source code of successful games is lost, but often proven true when it comes time to re-release or “remaster” classics. A recent example is Final Fantasy VIII, vanished by Square-Enix’s fire-and-forget philosophy of version control and remade from scratch. Even more amazing, a single programmer, GalaXyHaXz, spent four months reverse-engineering classic 1996 action RPG Diablo, recreating it from the ground up without the original code at hand. This video explains how he did it–and what it means for game preservation.