During World War II, as the number of British soldiers being held prisoners behind enemy lines escalated, the British secret service enlisted a most peculiar partner for help: The board game Monopoly.

Secret service agents knocked on the door of Norman Watson, who owned the only Monopoly game factory in Britain at that time. He also owned the only company to have mastered the art of printing on silk material. Together they would play a part in rescuing an estimated 35,000 war prisoners during World War II. 

The plan was to hide useful tools inside Monopoly boxes which can help in the Allied prisoners escape. Miniature versions of tools such as a compass and a small metal file, along with essentials such as money, were hidden away inside the Monopoly tokens and hotels. This was done in a sealed-off part of the factory and workers who were involved in production was sworn to secrecy. It helped that most workers were afraid of going to prison themselves if the Germans ever caught word of the factory's part in helping the Allied forces.

But the most important of all these hidden pieces was a map made of silk. Even before the World War II, silk had always been a sought-after material of war to print military maps on as they wouldn't tear easily or dissolve in water like paper. It also wouldn't rustle. Imagine trying to open up a smuggled paper map but the paper's rustling sound attract the attention of enemy guards! 

It’s the sort of thing that could get a man killed...

It’s the sort of thing that could get a man killed...

It also helped that boredom proved to be quite a problem in German prisoner-of-war camps. The German Nazis were concerned that the prisoners would use the time to plan their escape or cause uprisings, and so they allowed humanitarian groups to distribute charity care packages to prisoners. The Monopoly game looked too innocent to raise any suspicion and was allowed through to all of the camps in an attempt to keep the prisoners calm and entertained. 

To the German eye, the board game seemed normal. But the prisoners have been trained that in the event of capture to be on the lookout for packages from humanitarian groups, so they knew what to look for. 

All thanks to this ingenious and unorthodox plan, an estimated 35,000 Allied prisoners broke out of camps and found their way safely home. 

So the next time you're about to flip the Monopoly board because you're down to your last $10 bill, just remember that this game that can cause player to irrationally lose their tempers is also the same one that saved thousands of lives in the war.