During WWII, the manufacturer of the UK version of Monopoly, John Waddington Ltd., produced aWartime edition due to supply constraints. The rules were altered, pieces were replaced and a spinner was used in lieu of dice.
Reddit user flatcap_monty and his girlfriend recently obtained a ‘War Time Pack’ edition of Monopoly and shared a fascinating album detailing the differences.
Most interestingly, special POW editions of the ‘War Time Pack’ were produced by John Waddington Ltd., and distributed by fake charities to try to help Allied Forces escape. Secret maps printed on cloth or silk (they don’t make noise, could get wet and be stuffed easily), escape tools and other useful information about the war were hidden inside the actual box and even the board itself.