Violent games
I hate to be the one to say this but there is a reason why they write parental guidance on the boxes of video games that are violent in nature. There were studies that show that after a child plays a violent video game, it arouses their amygdala, a part of the brain that has something to do with emotional arousal.
Chances are, when they get into a slightly similar situation that appears like the video game, they may end up doing something violent as a reaction to the situation.
As a parent, it is their duty to do what it takes to lecture a child that a video game is merely just a video game designed for entertainment, fun and some logic. It is not meant to be practiced in real life.