Microcorruption — You’ve been given access to a device that controls a lock. Your job: defeat the lock by exploiting bugs in the device’s code. Fun way to learn assembly language and debugging.
Unicode’s Ghost Characters — after the JIS standard was released, people noticed something strange—several of the added characters had no obvious sources, and nobody could tell what they meant or how they should be pronounced. Nobody was sure where they came from. These are what came to be known as the ghost characters.