The Soldier Key is used to unlock various doors in the Forest of Fallen Giants:
- The door to gain access to the second encounter with The Pursuer, located through a passageway and to the right beyond the Old Ironclad Soldier.
- The door directly above the Cardinal Tower bonfire, reached by climbing the stairs in the same room. This door can also be broken open with a weapon, so the key is of little use here.
- The door down the ladder and across the small bridge below the Cardinal Tower bonfire. Used to obtain the Ring of Restoration.
- Allows access to the Soldiers' Rest bonfire.