Mcdonald's announced that its Monopoly promotion is coming back this year. Mcdonald's ran its first Monopoly-themed promotion in 1987. You'd collect scratch-off tokens corresponding to different properties on the monopoly board. Different menu items would yield chances at different property tokens or an "instant win" for something small like a free coffee or fries.
If you matched all properties in a color set (e.g., Illinois Ave, Indiana Ave, and Kentucky Ave), you'd win a grand prize.
The chances of acquiring any property are about 1 in 11 — except for one piece of every set. The chances of pulling the rare piece in these sets range from 1 in 450,000 (Mediterranean Ave, $50 gift certificate) to 1 in 450,000,000 (Boardwalk, $1 million).1
These types of games are called Complete Gacha (Kompu Gacha) and were so popular in Japan that they are now banned. There are variations of the Gacha game –
using in-game currencies to receive a random item
complicated conversion mechanisms or exchange rates
increasing odds if the user spends in bulk or has many consecutive losses
known or unknown win probabilities
Loot boxes are another form of Gacha games that show up in video games. Roblox is one game where a significant portion of games are play-to-win with loot boxes.
1Probabilities from the 2014 game – source.
2Your real chances of winning the grand prize from 1989-2001 were zero – if you didn't know "Uncle Jerry". He was the chief of security at a subcontractor that McDonald's used to run the promotion. "Uncle Jerry" was secretly stealing the winning pieces and distributing them to his friends and family. Eventually, the Mafia got involved. There's a documentary on HBO about it called McMillion$.