Guards are very easy to kill, however, if the player wants to obtain a gold rank, they must not kill any of the guards as part of an optional objective. To complete this objective, the player must either avoid them, or sneak up behind them and knock them out with a sleeper hold. Should the player engage one, they may fight him barehanded until he falls to his knees, at which point he may be put in the sleeper hold. Note that punching or kicking an unconscious security guard will result in a kill.
If the player does decide to kill them, they will die very quickly since they have low health and most of the nearby weapons are bladed and do a lot of damage. Some guards wield a Baton that may be picked up and used. Be careful if the guard drops his baton, as he may grab a stronger weapon dropped from enemies or from a display case.
- When in combat with the player, the guards will behave exactly like an Influenced. They will attack aggressively, grunt madly, and even taunt the player.
- Many security guards can be found engaging in unscripted fights with Vandals. It should be noted that if a Vandal kills a guard, it will not hurt the player's optional objective.