Under the strictest of secrecy, in a securely guarded and inaccessible old workshop on the grounds of Waddington's, a group of sworn-to-secrecy employees began mass-producing escape maps, keyed to each region of Germany or Italy where Allied POW camps were regional system). When processed, these maps could be folded into such tiny dots that they would actually fit inside a Monopoly playing piece.
As long as they were at it, the clever workmen at Waddington's also managed to add: 1. A playing token, containing a small magnetic compass 2. A two-part metal file that could easily be screwed together 3. Useful amounts of genuine high-denomination German, Italian, and French currency, hidden within the piles of Monopoly money!