The boys had congregated on the Schönengrund school grounds in the canton of Appenzell Ausserrhoden for some fun with their new air rifles, online news site 20 Minutes reported.
“We just wanted to have some fun with our air-soft guns,” one 18-year-old boy told the website.
The three boys arrived at the grounds on Saturday night with two air pistols and air rifles and began to play their war imitation game. The rules were simple: whoever got hit, was out.
The trio had played several games before police showed up at around midnight.
The police foot patrol first came across one of the players, a 20-year-old man, sitting on a bench with his weapon, his face covered by a balaclava. He was immediately overwhelmed. Another of the trio then emerged firing at police, believing it was one of his teammates.
Police drew their weapons but luckily did not shoot.
“Probably only because they could see straight away that they were only air-soft weapons,” police spokesman, Willi Moesch, told 20 Minutes.
“We were very lucky,” Moesch said. “Air-soft guns are hard to distinguish from real ones, even for professionals."
In a statement, police later warned against using such deceptively-real looking weapons and reminded the public that playing such games on public property was against the law.
“The police may have been persuaded to use their service weapons,” the statement said, alluding to the near-fatal disaster that had only narrowly been avoided.
The boys, all aged between 18 and 20 years, will now have to answer charges for breaching Swiss weapons law.