Coded messages from within the camps were sent to fictitious addresses set up by MI9 for various charitable organizations. Thank you notes from grateful game players were often messages to MI9 informing them of what had been received and what additional help was needed. Games such as Monopoly, checkers, chess, and others often included other escape materials such as money, files, magnetized metal for the manufacture of compass needles, camera film, and other assorted paraphernalia. Prior to the United States entering the war the United States Playing Card Company was contracted to produce standard and pinochle card decks in which the playing cards concealed escape aids.
The Germans, being meticulous record keepers, allowed the prisoners to sign receipts for many of the items, having been persuaded by the senior prisoner officers that so doing allowed the Red Cross and other organizations to confirm that their work was being allowed and the Geneva Convention followed. The receipts helped MI9 to confirm what materials were being delivered to the prisoners and in what regional areas. MI9 could thus confirm that maps of Poland were being received in Poland, for example.
Many prisoners who escaped successfully – inexplicably the non-baseball-playing British referred to a successful escape as a home run – ended up joining MI9 upon return to England, enhancing the branch’s knowledge of conditions within the camps and their ability to exploit them. Others worked with the Secret Intelligence Service (SIS) to document escape routes set up by the various underground groups in Europe, information then forwarded via Monopoly and other games to the camps. One such officer employed by SIS was Navy Commander Ian Fleming. After the war, Fleming drew on his intelligence work with SIS to create Commander James Bond in a series of novels and short stories.
Not all troops were briefed on the details of the Monopoly deception due to the need to maintain secrecy, only screened officers and non-coms were aware of the program. Senior officers in the camp decided who was to be made aware of MI9s intervention. But all troops were made aware of escape assistance being provided in some manner, helping to motivate prisoners to attempt to escape.
Prisoners who successfully escaped were often put to work briefing Allied troops on existing underground units and escape routes in the hope of allowing them – particularly airmen who may be forced to bail out over German-held country – to evade capture in the first place. By the end of the war bomber crews flying over Germany were equipped with silk/rayon maps sewn into their clothing, helping them to find their way to safety. Evading capture grew in importance later in the war as the Allied bombing campaigns caused increased hostility from the German populace towards American and British airmen.
By the end of World War II, nearly 36,000 prisoners had successfully returned to England after either evading capture or escaping from German prisons. Nearly all of them did so by crossing the borders of neutral Switzerland, Sweden, or Spain, where they were turned over to the British or American consulate for repatriation. MI9 and its Monopoly ruse were certainly not responsible for all of them, and an accurate estimate of how many men made it home as a result of the materials sent in Monopoly and other games is impossible. The branch was dissolved in 1945 and many of its records destroyed. What is known is that MI9 produced over 240 individual maps of sections of the European and North African theatres, with at least 1.7 million copies distributed to prisoners via Monopoly and other games.
Sources For Further Reading:
Mental Floss – How an Intelligence Officer Used Monopoly to Free POWs
The British Library – Escape And Evasion Maps of World War II
Helen Fry – MI9: A History of the Secret Service for Escape and Evasion in World War Two
The Atlantic – How Monopoly Games Helped Allied POWs Escape During World War II
ABC News – Get Out of Jail Free: Monopoly’s Hidden Maps
Snopes – Were Escape Kits Smuggled to WWII POWs in Monopoly Games?