: Extreme compression often achieves small file sizes by stripping out vital game data. Audio/Video

Highly compressed games, often called "repacks," use advanced algorithms to shrink game data for easier transit.

Do search for "COD Black Ops 2 PC highly compressed download UPD" — those results lead to scams. Instead:

Inside the downloaded folder, look for a CODEX or RELOADED folder. Copy its contents into the main game directory, overwriting existing files.