The number 7 is seen as lucky in slots and pop culture partly because of...

https://wiki-view.win/index.php/Is_7_Actually_Lucky_or_Just_a_Tradition%3F

The number 7 is seen as lucky in slots and pop culture partly because of classic reel symbols like 777, which often signal a big win. It’s also tied to the seven-day week, making it feel familiar and lucky to many people playing games like those on MrQ.