The problem being that small discreet pistols often do shit damage and big gorilla's often have a lot of hit points or endurance. So the plucky woman reporter grabs a hammerless .32 revolver from her clutch and covers Mickey 'the Rhino.' The revolver does 2d6 damage and as Rhino has 12 hit points he takes the shot and wrings the plucky woman reporter's neck. What can I say? He's a bastard.
Players are often guilty of making similar choices (instead of roleplaying an aversion to being plugged.)
Covering someone is a great way to set up a tense scene. But to do so you have to have a chance to come out on top and a chance to get screwed over and a few in between results. There is some justification in Traveller and other Old School games. For example Traveller says that an unconscious opponent or someone restrained and incapable of resisting can be finished off with a single blow or shot by an attacker at close range. No die roll necessary unless the character is making an unarmed or weakened blow. That's strong stuff. Imagine finishing off a stunned marine in TL 12 battledress with a TL 2 dagger!
Obviously a character being covered is still capable of resisting, just at a marked disadvantage. Killing the person covered is not automatic (we want to give people a chance, it makes for a good game.) But making a grab for the gun is going to have consequences if you fail.
House Rule Covering a Prisoner
A defender can be covered at short or close range by a guard or opponent who achieved surprise, has a ready pistol or rifle and is not in danger of being attacked himself.
If the defender decides to rush the guard he must first make a morale roll with all the appropriate modifiers. If he doesn’t make the roll he is intimidated and may not make do anything except follow instructions until the situation changes (i.e. the guard is distracted, something worth risking his life for happens etc.)
If the defender decides to rush the guard or otherwise provokes him the guard fires with a +1 dm. In addition the defender does not benefit from armor (ignore damage resistance or dm to hit as the guard basically has the weapon trained on the softest parts of the opponent’s anatomy or armor.) If the opponent has no armor then the shot does maximum damage.
The covering fire does not count against the guard’s attacks. He can make another normal attack that same round and probably will against the defender.
A single shot weapon can only cover one person. Characters may cover up to 3 adjacent defenders with a semiautomatic weapon. An weapon capable of autofire can cover a number of defenders equal to its burst number. Every defender in excess of this imposes a -1 dm to attacks.
Optionally a character may cover a single opponent at close range with a melee weapon, (laying the blade across their throat, jabbing a cudgel in their kidneys, but this requires the character to make a successful brawling or weapon attack. As above armor does not modify the hit roll and the attacker is at +1 dm.