.pk3

Compressed game data file used by games based on the Quake III engine (id Tech 3), which was developed by id Software; may contain maps, textures, audio clips, or other data used for gameplay; can be modified to create custom game content.

PK3 files are similar to .PAK game data files, but are based on a newer format. Since PK3 files are compressed using Zip compression, they can be renamed with a .ZIP file extension and extracted using a file decompression program such as Corel WinZip or PKWARE PKZIP.

Quake III PK3 files should be saved in one of the following directories: quake3/q3ut3, quake3/baseq3, or quake3arena/q3ut3.

Important: Examples of games that were developed using the id Tech 3 engine include Quake III Arena, Star Wars Jedi Knight II: Jedi Outcast, Soldier of Fortune II: Double Helix, Return to Castle Wolfenstein, and Call of Duty Classic.