The security guard uniform consists of a blue shirt, black tie, dark blue pants, black assault boots, equipment belt, armor vest and helmet. However it is proven later that the clean-up crew will terminate any Black Mesa employee and does not work at all with the Security Force. In the event of an emergency, security guards are required to cooperate with the ' military' and ' trained assassins', referred to as 'a dangerous and very efficient clean-up crew'. They are accommodated in specific facilities, such as Area 8 Topside Dormitories, where Barney Calhoun lives. Guards always have to report to their related facilities, such as Sector C's Area 3 Medium Security Facilities, before starting their duty. They also oversee security checkpoints, such as Area 9 Security Checkpoint located along the Black Mesa Transit System.

They often stand near doors requiring a special access, and will refuse or grant this access depending on the person wanting to go through, related to the person's clearance level or if they have the required equipment to proceed. They have different ranks and are granted a different security clearance specific to their duty, with an average clearance of Level 3, as well as colored shifts in specific Areas of specific Sectors, such as Red, Orange, Yellow, Green, Blue, Indigo, and Violet Shifts. Security guards oversee the security throughout the facility. Security guard stationed in Sector C next to a retinal scanner.

Half life guard duty