A bug is an error, flaw, mistake, failure, problem or fault in a game that prevents it from working as intended. This may include things such as graphical flaws, spells not working correctly or features not working properly.

Bugs are often fixed in game updates. If you find a bug you can visit the support section of the official Guild Wars homepage to report it.

For a current list of known bugs, see Category:Bugs.

Skills that contain anomalies are listed at List of skill anomalies.