From Sega Retro

A more catastrophic example of a bug, which has crashed Flashback with a "Line 1111 Emulator" error.

A bug, sometimes referred to as a glitch, is a term generally used to describe programming faults or mistakes in computer/console software or systems. Bugs can range from very minor oddities, such as a palette or animation error or a sort-term quirk in gameplay, to more serious cases such as a massive decline in performance or a crash. Some bugs may not be apparent, often requiring the player to go out of their way and do things the programmers likely wouldn't have expected the player to do. Some bugs in a game are fixed in later regional/revisional releases or, in the case of more recent games, official patches distributed online by Sega.

Whether they are minor or game-breaking, they are all documented in the pages under this category. To add a bug to a page, use the Bug template.