The Black Mesa Security Forces are the force that protects the Black Mesa Research Facility and keeps order, as well as performing general maintenance. It mostly consists of security guards armed with 9mm pistols and wearing bullet proof vests, but it also includes mechanized defenses such as Ceiling Turrets. They appear constantly throughout the G-man Squad and Freeman's Mind series. The security guards are killed by the G-men in their attempts to stop the resonance cascade, while Freeman usually simply talks to them, while occasionally going to them for fire support.
In the G-man SquadEdit
Security guards appear occasionally in the G-man Squad improvised comedy series. Their first appearance is in Operation: Black Mesa, where they are among the many Black Mesa staff slaughtered by the G-Men by crowbars or any other weapon. Security guards also appear in Science, where an injured guard who is revived by a scientist is shot by the squad, while another guard is shot by a G-man on top of an elevator platform. The G-Man also are shown breaking two sentry guns with their crowbars in "Grunts". They also constantly get blown up by tripmines placed by both them and Black Mesa.
In Freeman's MindEdit
Freeman runs across guards less frequently than scientists, but still fairly often. He shows less contempt towards them then most other characters (and creatures) in the series, although this is not to say he does not get very mad at them at times. He considers them generally more helpful then the scientists, do to the fact that they occasionally kill off aliens for him. However, he still shows more anger and dissapointment with their deaths then he does regret, (Freeman: (having just witnessed a guard get killed by a zombie" "aawwwwww. You people never fail to dissapoint me.") He also sometimes shows contempt towards them for their incompetence, such as one guard who refused to take cover from a .50 caliber machine gun (Freeman: "Some partner you turned out to be! What good are you now?!"). He hates sentry guns very much, and repeatedly doubts why Black Mesa even has them. He gets shot by one in Episode 9, and as a result he is very cautious about them. He never knew what the tripmines did until episode 22, where he saw several soldiers get killed by running into them.