In Monopoly's case, those consequences came during World War II.

During the war, large numbers of British airmen were felled over enemy airspace and then held as prisoners behind enemy lines. Germany, however -- in part as a nod to the Geneva Convention -- allowed humanitarian groups like the Red Cross to distribute care packages to those prisoners. And one of the categories of items that could be included in those packages was "games and pastimes." So the Allies took military advantage of this human kindness: Posing as "charities" (one of the better fake names: the Licensed Victuallers Prisoners Relief Fund), they sent packages to their POWs that featured clandestine escape kits -- kits that included tools like compasses, metal files, money, and, most importantly, maps.

And: They disguised those kits as Monopoly games. The compasses and files? Both disguised as playing pieces. The money, in the form of French, German, and Italian bank notes? Hidden below the Monopoly money. The maps? Concealed within the board itself. "The game was too innocent to raise suspicion," ABC News's Ki Mae Heussner put it -- but "it was the ideal size for a top-secret escape kit."

To develop that kit, MI9, the British secret service unit responsible for escape and evasion, conspired with John Waddington, Ltd., the U.K. manufacturer of Monopoly. "It was ingenious," Philip Orbanes, author of several books on Monopoly, told Heussner. "The Monopoly box was big enough to not only hold the game but hide everything else they needed to get to POWs."

But ... why Monopoly, exactly? How did the consummately American board game come to the service of British servicemen? Not because MI9 had a special affinity for American real estate -- or even for Scottie dogs -- but rather because Waddington had mastered a technology that no other manufacturers had: printing on silk. This was crucial: The Allies needed to be able to print their clandestine maps on a material that would be hardier than paper -- material that wouldn't tear or dissolve in water and that would be light enough for the user to pack into a boot or cigarette packet at a moment's notice. (Silk maps, which have long been in use among militaries, have the added advantage that they don't make noise as they're being held or stored -- an important attribute, when you're a prisoner in search of escape.) Waddington, as it happened, was already using silk-printing technology to create silk prints for things like theater programs.

And Waddington was also, as it happened, the licensee for Monopoly in the U.K.

So, through a little bit of coincidence and a little bit of cunning, a game-based escape plan was hatched. Before departing for missions, Royal Air Force airmen were told that, if they happened to be captured, they should look for Monopoly games in the "care packages" sent to them -- and for the escape maps and kits that were hidden within them. The "special edition" Monopoly sets would be designated with a red dot on the Free Parking space -- something that would look to anyone who didn't know about the trick like a standard-issue printing error ... but which might, to a captured soldier, look something a little more like freedom.

Once they obtained the "playing pieces" within them, the soldiers were instructed to destroy the games -- in order to keep the ruse a secret from the Axis. And the trick, though unfortunate for those of us who would love to see its artifacts today, worked. British historians estimate that the MacGyvered Monopoly boards could have helped thousands of captured soldiers escape from their prison camps. Talk about, yes, getting out of jail free.

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