when a ladder must be climbed, or when indestructible obstacles are in the way).
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.