The number 7 is often seen as lucky in slots and pop culture because it’s been...

https://wiki-dale.win/index.php/Numbers_as_Cultural_Shorthand:_Examples_Beyond_the_Iconic_Seven

The number 7 is often seen as lucky in slots and pop culture because it’s been connected to good fortune for centuries. Classic slot machines, like those at MrQ, use 777 as the top winning combo