.GSC File Extension
File TypeCall of Duty Game Script
What is a GSC file?
File used by Call of Duty (CoD) games, including Modern Warfare 2 (MW2), MW3, MW4, and MW5; saved in a plain text format and may contain gameplay settings for maps, graphics, audio, and other gameplay properties often used for describing game maps.
GSC files are sometimes modified ("modded") by the game community to create custom content. However, this can result in banning from CoD servers if detected.