it's commonly thought that monopoly was invented by an unemployed Philadelphia salesman in the Great Depression. It makes a good story. But the concept was actually invented and patented in 1904 as the as theLandlord's Game, game of protest by a Virginia Quaker woman who was concerned about real estate being used to consolidate wealth. In that game,
The key difference was that you could not buy property in this game and become a landlord yourself. It was meant to show how wealth cyclically accrues to people who already have resources, so you basically just lost money. But it became a "folk game" in which people drew and printed their own boards based on the general idea, and made up their own rules (kind of how Monopoly is now - have you ever actually tried to play 'by the book'? It's a pain in the ass). One of the commonest iterations was to allow the purchasing of property. So the 'inventor' of the game really just took something that he came across that had no clear ownership claim, and patented it.