 Teams can use any available map and compass (but not GPS) for navigation and cell phones (but not radio stations) for communication.TMOU is organized by "Instruktoři Brno"—an informal group focusing on outdoor and experiential education.Since 2000 TMOU has inspired many other similar games in Czech Republic and beyond, e.g., 

At the moment, there community of outdoor puzzlehunt players counts several thousands in the Czech Republic, which has a population of 10 million people.