A BAK2 file is a backup file used by Starbound, an open, sandbox 2D space exploration game. It stores backup information for the game, which may be about a player character or spaceship. BAK2 files are helpful for recovering information in the event of a computer crash or corrupt PLAYER or SHIPWORLD file.

BAK2 files bear a compound file extension. The ".bak1" extension is added on to a file that it is storing information for, such as a PLAYER or SHIPWORLD file. For example, if the file is storing backup information for a SHIPWORLD file, the filename would be ab 07704dbcb4162646d4d93bbeef34df.shipworld.bak2. You can delete the ".bak2" extension from the filename and open the file as a SHIPWORLD file in Starbound. However, it is important that you do not change the string of characters preceding the extensions. BAK2 files can be found in the "player" folder in the "Starbound" folder. For example if you purchased Starbound through Steam, the BAK2 files are stored in the following location in Windows: C:/Program Files/Steam/SteamApps/common/Starbound/player NOTE: Starbound also uses .BAK1 and .BAK3 files.