To successfully change your game to English, you typically need both a modified localization.txt file and the corresponding English asset files ( Modified localization.txt localization.txt file in your main Black Ops III installation folder. The first line should be changed from (or your current language) to Direct Download
Steam should automatically begin downloading the Core English Depot. Method 2: Manual "Localization.txt" and File Replacement call of duty black ops 3 english localization txt download
English files for Black Ops III :: Call of Duty - Steam Community To successfully change your game to English, you