- Video report by ITV News Correspondent Martha Fairlie
Online shooting game Fortnite is said to be the most addictive game of all time, but is it dangerously addictive?
The free-to-download game, which involves up to 100 players competing in a battle royal-style last man standing match, has been downloaded more than 40 million times worldwide.
Child safety experts say parents should be aware of the potential dangers, not least because it takes away from precious study time.
Andy Burrows, from kid's charity NSPCC, said: "We know that one in four children have been contacted by someone that they don't know on apps sites and games.
"With fortnite we know that communication, through voice chat and text chat, is an integral part of the game experience and that's why it's really important that parents are aware of the risks of this game."
The game's design, its ease of communication and game-play, are what make it so successful and appealing to teenagers.
Video games journalist, James Jarvis, said: "Fortnite's really addictive because basically it's a free to play game that doesn't make any difference whether you've played it for one hour or 100 hours.
"You're always going to get the same experience, you drop on to the map at different points, you can go to different places, you collect different weapons and items on your way and you meet different players along the way."
Parents are concerned about what effect the game has on the children who play it and even some of the kids are worried.
Teenager Louis Cooke said: "I've got my GCSEs coming up in a couple weeks and I guess that is a bit worrying how I'm playing the game a lot even though (my exams) are coming up."