Enclave Squad Sigma

 is a special unit of Enclave Soldiers which are added to Fallout 3 in the Broken Steel add-on. The Sigma Squad is assigned to protect the Mobile Base Crawler in case of an attack, which happens when the Lone Wanderer infiltrates the base. The squad consists of approximately 5-6 soldiers using different types of specialties, led by the Enclave Sigma Leader. After (and if) an alarm sounds in the Mobile Base Crawler, the squad arrives and immediately attacks the Lone Wanderer.

Appearances
appears in the Fallout 3 add-on Broken Steel.