Praetorian guards are the elite personal bodyguards of Caesar. A group of them also serve as the bodyguards of Caesar's Legate, Lanius. Praetorians focus exclusively on unarmed combat in battle, and can see through disguises. The leader of the Praetorian Guard is Lucius, the third most powerful man in Caesar's Legion.
Their name refers to the ancient Roman Praetorians, bodyguards of a general's tent (praetorium) and, in later centuries, of the emperors.
Caesar explains that his Praetorians are hand-picked from amongst the ranks of those Legionaries who have served for long enough and have killed enough men to qualify as centurions. Those invited to join the Praetorians must pick a current member of the Praetorian guard whom they believe is the weakest, and challenge them to an unarmed duel to the death. If the invitee wins, he takes on the position.
Personifying Caesar's martial philosophy, the Praetorians fight using only unarmed combat. Lucius explains that weapons or firearms may break or jam, but a true warrior can always rely on his innate skills. Regardless, Praetorians still wear ballistic fists to give their punches devastating impact beyond what a normal human blow can inflict.
Praetorian guards have a version of the Toughnessperk, which grants them 10% Damage Resistance in addition to the 12 Damage Threshold from their armor. It is very unusual for human non-player characters in the Gamebryo Engine Fallout games (Fallout 3 and Fallout: New Vegas) to have perks.
Praetorians are 30% faster than a normal non-player character.
Despite what Lucius says, the Praetorians in a Legion Assasin party will likely use a firearm (usually an assault carbine) to kill the Courier, unlike the ballistic fists that Praetorians are supposed to use.
The image on the card of the Fallout: New Vegas Collector's Edition Caravan deck looks exactly like a centurion rather than a Praetorian guard.