A brand new exhibition at the Museum of Childhood in London is taking a special look at war games.
Lots of kids play with toy guns and in the past, warring countries even created toys to prepare children for the coming conflict.
But many parents and teachers discourage kids from war games: they think it can make fighting seem cool.
Others, however, believe these games help children learn right from wrong and the consequences of violence.
Send us your comments
We asked whether you're allowed to play war games for fun.
Is it just a bit of fun or do you think it can make violence seem cool?
Here's a selection of your comments.
"I think it's ok to play with war games because it gives us kids the education and the experience of the war and make us realise what are soldiers are going through."
Luke, Rhyl, Wales
"I don't think kids should be playing with guns and swords, because it has a bad influence on younger children. All my brother does is play with guns and play violent video games."
Jess, Maidstone, England
"My mum grew up in the Belfast 1970s conflict, and they lived in fear of the guns so much they moved house. Now she won't let us (my sister and I) even hold our fingers like a gun. I understand why and agree."
Amy, Worcester, England
"I think it's ok, if they don't do it in real life. I play war games with my friends, but we are all switched on enough to know it's not real and we have no feelings of violence towards people in everyday life."
Toby, Cradley, England
"I do not think that it is suitable for children to play war games because even if they are playing they might have nightmares."
Matilda, Guildford, England
"I think it's ok because it's games and kids have the right to play whatever they want. As long as they are playing and no violence is implicated."
Matthew, Selby, England
"I think it is okay to play with toy guns because it gives children an experience of what some people are doing every day and means we don't turn into criminals."
Daniel, Swindon, England
"I rarely play war games with my friends 'cause I know the consequences because my brother is in the Army."
Rosie, Staffordshire, England
"I think they're being too overreactive. I play with Nerf guns and I LOVE them but I know from right and wrong."
Harry, Fareham, England
"I play war games all the time with my mates and we love it. It does sort of make violence sound fun, but just in a game. But we know not to make actual violence in the future as you can get seriously injured."
Adam, Essex, England
"I don't think toy guns should be allowed because there is too much violence in the world today and some people could find it offensive if they see them."
Rachel, North Lanarkshire, Scotland
"I play war games with my mates and on games consoles, but I know I shouldn't do it in real life."
Alex, Bath, England
"I don't think it is okay to play war games. These toys represent violence in very young children. Even the 4-5-year-olds at my school talk about guns."
Rachel, Essex, England
"I do play war games with my friends but I don't like war. I just play them for fun."
"I think it is okay to play war games because if the child wants to be in the military forces fighting against other countries, then it's definitely good practice."
Christina, Inverness, Scotland
"I'm not one who plays with them much, but I am still allowed to play with them - my parents have nothing against it."
Nathan, Southampton, England