When Carl-Magnus Helgegren's young sons revealed how obsessed with Call of Duty they'd become, he decided it was time to teach them some things about war. And have them taught by people in the business.
"They were talking to me like it was a cool game, and everybody else was playing it, and it had all these cool weapons.", he told The Daily Dot. "Then I started asking them, 'What kind of weapons are there?' And they started telling me these, you know, brand name models of different automatic rifles."