By day, Bartosz Bruski works in computer forensics, but in his down time, the 29-year-old unwinds by heading to a trailer park outside Warsaw, where he directs a group of around 60 Polish people who pretend to be ordinary Americans – people from Ohio, to be exact. You might think LARPing (short for live action role play) basically means a bunch of people dressed in medieval outfits, recreating historical battles. Instead, Bartek and his fellow LARP enthusiasts turn a peaceful holiday resort in a Polish forest into an American trailer park, with dozens of participants who stay in character with...