Adolf Schlussel was a minor antagonist in Call of Duty: Black Ops: Declassified.
Schlussel was called Dr. Friedrich Steiner's protegè by Jason Hudson, which implies a history between the two. He put forward a plan to bring back Steiner's Project Nova at Mt. Yamantau. Hudson's contacts heard rumours of the project's revival and Hudson sent in a small team to Mt. Yamantau to stop it in the Winter of 1977. Frank Woods, the team's sole survivor, killed all the soldiers guarding it and killed Schlussel, stopping Project Nova once again.
- Schlussel is German for "key".