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

https://www.bright-bookmarks.win/the-number-7-is-seen-as-lucky-in-slots-and-pop-culture-because-it-often

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.