The Nightstick is a non-lethal weapon. It is carried as a compliance tool and defensive weapon by law-enforcement officers, correctional staff, security guards and military personnel. In many cultures, they are highly symbolic of law enforcement and are rarely used with the intention to kill.
In Mortal Kombat (2011), he wields the Nightsticks during gameplay and uses it with combos, special moves and his X-Ray Move. However, they were always called Batons rather than Nightsticks in this game.
In Mortal Kombat X, Cassie Cage wields an extendable nightstick, using it in many of her kombos, her X-Ray and her "Selfie" fatality.