A safety was a device present on some weapons that prevented them from being fired accidentally.
Upon being invited to join the Commandant's Cadets, a secret society at the Arkanis Academy, Zare Leonis was instructed to kill Penn Zarang, a poorly-performing cadet, in order to prove his worthiness. He was to shoot the cadet during a training exercise to make the incident appear to be an accident. To aid in accomplishing this, he was provided with an E-11 medium blaster rifle and instructed to engage and disengage the weapon's safety three times for it to fire full-power shots.
The NN-14 blaster pistol given to Rey by Han Solo was one such weapon equipped with a safety switch. When she attempted to use it against Unkar Plutt and his thugs, she found it did not work because she had not disengaged the safety, a feature she was unaware of. She later disengaged it before using the weapon against First Order stormtroopers.
In the film Star Wars: The Force Awakens, Rey is shown disengaging her weapon's safety before firing at stormtroopers. The film's novelization provides a bit of background by showing Rey attempting to use the weapon against Unkar Plutt, but being foiled by the safety being engaged. This sequence is also present in one of the film's deleted scenes.
In the film Star Wars: The Force Awakens, Rey is shown disengaging her weapon's safety before firing at stormtroopers. The film's novelization provides a bit of background by showing Rey attempting to use the weapon against Unkar Plutt, but being foiled by the safety being engaged. This sequence is also present in one of the film's deleted scenes.