How did Monopoly's gameplay change during World War II to aid prisoners of war?

During World War II, the popular board game Monopoly underwent a fascinating transformation to serve a very specific purpose beyond entertainment. The British secret service, in collaboration with the game’s publisher, devised a clever scheme to use Monopoly as a vehicle to aid POWs in escaping from German camps. Special editions of the game containing hidden maps, compasses, and real money were smuggled into these camps under the guise of being regular parcels. This unique adaptation had a significant impact and posed considerable risks, making it an intriguing aspect of both board game history and wartime strategy. How did these innovative changes to a simple board game contribute to escape efforts, and what were the implications for those who were caught with such contraband?