During WWII, the Nazis did something un-Nazi-like. They let Allied prisoners of war play board games. The British government was even allowed to send it to incarcerated soldiers for a game or two.
One of the games it sent? Monopoly.
Inside the box? Tools for escape.
Specifically, the British government, with the cooperation of the game’s publisher, hid real bank notes among the Monopoly money, Compasses, metal files, and a folded silk map – which was less likely to disintegrate than a paper one – were also concealed inside the box to help the POWs flee their captors. It worked; the soldiers escaped.