From the Ethicist:
Secular culture, like religious culture, has its totems and taboos. For all of us, objects — a crucifix, a wedding ring, a sports car — take on meanings beyond their physical reality. So it makes sense that, for you, toy guns symbolize the harms you associate with real guns: the desire to exert control over others through intimidation or lethal force, the prospect of injury and death.
That’s not to say that there aren’t any risks associated with these toys in themselves. For one thing, their projectiles — even the softer, slower Nerf ones — can damage your eyes if you are hit and aren’t wearing protective glasses. There’s also the risk that these toys can be mistaken for real weapons. Though look-alikes are required to have an orange tip, that measure may not suffice, and replicas are banned in some jurisdictions. In 2016, two years after a police officer killed Tamir Rice, a 12-year-old boy who was playing with an airsoft replica handgun, a Washington Post analysis found that 43 people with toy guns were killed by the police in the previous year. Forty-three people a year is, of course, 43 too many. But given that millions of people use toy guns (Nerf said it sold 40 million blasters in 2020), and given that your son, with his eye protection, seems to be safety-conscious, his being physically injured by his war games probably shouldn’t be high on your list of things to worry about.
Then there’s the concern that these activities enable “a love of violence,” as you say. I won’t try to summarize the literature on whether playing violent games, either onscreen or in real life, encourages violent behavior. This is a much-disputed question. We know that in the years after young people started playing violent video games, rates of actual youth violence dropped; in Japan, where, granted, it’s difficult to own a gun, actual gun violence is extremely rare, and kids routinely play war games with toy guns. So it’s hard to draw a straight line between play violence and actual bloodshed.
Most teenagers, like most adults, do seem able to distinguish between make-believe and real life. Playing a killer doesn’t incline you to become one. A good thing, too. A nephew of mine is an actor, and often enough, when I catch him on TV, he’s holding a weapon or facing down one. (He seems a gentle soul off set.) If you did somehow get your son to stop these outdoor pursuits, I bet he would be devoting that time to first-person-shooter games, and this wouldn’t have the advantages of building local friendships in the open air.
Which brings us back to those totems and taboos. Part of what is at stake in your conflict with your son is, as you say, symbolism: Guns are at the center of the great partisan divide in our society. The Second Amendment has become a shibboleth of conservatives, just as gun control is a shibboleth of progressives. Our country has many more guns than people, with ownership concentrated in the hands of about a third of the population. Rational discussion of how to mitigate the dangers of all those firearms has been difficult.