The TAR-21 is not available until right at the end of Chapter 13: Adams. Before going up the stairs and completing the mission, Lugo's TAR-21 lies in a nearby tent, where it can picked up by Walker. As such, there is only one obtainable TAR-21 in the entire campaign. Ammunition for this weapon can only be gained from ammo crates and executions.
The TAR-21 is unlocked at level 19.
- The TAR-21 was originally supposed to be used by Adams, but was given to Lugo in the final game.
- The TAR-21 originally had a red dot sight attached. In the final game however, the SCAR-H's iron sights were added instead.
- In concept art, the TAR-21 was being held together with bands or tape, similar to the M249 SAW and Scout Tactical.