777 Casino: Real Money Games 17+ - App Store
777 is used on most slot machines in the United States to 4️⃣ identify a jackpot. As it is considered a lucky number, banknotes with a serial number containing 777 tend to be 4️⃣ valued by collectors and numismatists. The US Mint and the Bureau of Engraving and Printing sells uncirculated 777 R$1 bills 4️⃣ for this reason.
777 (number) - Wikipedia
To play 777, follow the HOW TO WIN instructions: Reveal a set of 4️⃣ any three like-colored "SEVEN" symbols in a row to win the corresponding prize for that row. Reveal two sets of 4️⃣ three like "SEVEN" symbols in a row to win double the prize.
777 | A Fast Play Game - Illinois Lottery