When a hero carries a handgun, he or she will tend to wield it and sometimes fire it in one hand. Perfect for still photo opportunities where the shooter's arm is bent above and behind their head and the gun is brought down to aim and fire. Even more cool is firing a gun sideways. The exception is if they are military or police officers, where they will use two hands. Unless they've gone rogue and/or are desperate. And sometimes the hero will have a gun in each hand. Or a sword in the other. For really big melee weapons being used in one hand, see One-Handed Zweihander.