(Mental Floss) -- Park Place, Boardwalk, and a hidden map with a secret escape route? For Allied POWs during World War II, Monopoly® games came equipped with real-life "get out of jail free" cards. During World War II, the British secret service hatched a master plan to smuggle escape gear to captured Allied soldiers inside Germany. Their secret weapon? Monopoly boxes. The original notion was simple enough: Find a way to sneak useful items into prison camps in an unassuming form. But the idea to use Monopoly came from a series of happy coincidences, all of which started with maps.
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Monopoly board games helped Allied troops in WWII
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Red Cross gave special games to troops in POW camps
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They contained maps, compasses, money
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The troops used the items to escape to safety
@placeholder officials feared paper maps might draw the attention of German troops, so they turned to an unlikely source for help -- silk.