It’s 4am, and I’m standing in a partially-demolished abandoned building 40 kilometers outside of Kyiv, Ukraine. Broken glass, splintered wood, and rotting pieces of insulation are everywhere. Fifty feet above the rubble-strewn floor, a man free climbs a metal girder, flashlight clenched in his teeth. The place is swarming with teams of Ukrainian men and women, ranging in age from 18 to 50, armed with walkie-talkies, headlamps, and utility belts, and all looking for something: a 2-inch code or phrase that’s been stenciled somewhere. Or a set of numbers that can only be read under a blacklight. Or a seemingly disconnected phone that, once picked up, transmits instructions to the listener.

This is Quest, one version of a popular set of games invented in Eastern Europe and referred to varyingly as “Encounters,” “Quests” or “Night Races,” depending on the format. The games tend to defy comparison to western games, but one legend implies that the founder was inspired by David Fincher’s 1997 classic “The Game.” While each of the myriad formats are unique in their own way, they all share the same basic framework. Teams of players on site (typically with access to a car) work with additional players online to solve puzzles and progress through the game.

While easier games may last just a few hours, the more complex permutations can last entire days and span hundreds of kilometers. Organizers utilise disused factories, decommissioned military installations and abandoned buildings, of which there is no shortage in the former Soviet Union, to host their games which often include over a hundred players.