Luckygame777 Home > Blogs > How to Play 777 Slots Online. How to Play 777 Slots Online. Let’s talk about the exciting world of 777 Slots. Whether you’re a new or experienced slots machines player, you may have seen the lucky number 777 used to symbolize the most popular free slots games.. 777 Slots is a term that refers to any slot machine using 7 as one of the symbols you must line up to win a jackpot.