Gamblers are the most superstitious people on earth. In a telephone survey held in Vegas, 80% of the gamblers confessed to having superstitions. There are probably as many gambling superstitions as there are gamblers, yet some superstitions are widely shared across cultures and countries. Here are 18 most popular gambling superstitions from the UK and around the world. Rabbit's Foot: Gamblers believe that carrying a dead rabbit's foot would bring good luck. It's not so lucky for the rabbit though, with some 10 million of these barbaric charms selling annually in the US alone. Clover Leaf: This less cannibalistic charm is also reputed to bring good luck in casino gambling. I tried it with online gambling by changing my wallpaper to a clover leaf, and the results weren't too bad. Walking Under a Ladder: If you've walked under a ladder on your way to the casino, better take a U-turn and go back home. You have attracted bad luck, or so goes the superstition. Black Colour: This one should be an obvious. Black colour denotes death and darkness. Most gamblers don’t wear black while gambling. Dog…Crap!: Some superstitious gamblers would walk away from craps tables when they spot a dog nearby. Rare situation, but be cautious. Red Scarf: Asian gamblers believe wearing a red scarf would help them charm Lady Luck. I guess the charm might not be so lucky during a bull-running festival. Black Cat: This one's so clichéd I'll just skip it. Freaking Numbers: If you're gambling in China, numbers can get on your nerves. Number 18 is lucky because it sounds similar to "will definitely prosper" in Cantonese. Numbers 3, 6, 8, and 9 are lucky, while 4 sounds like "die". A Tap on the Shoulder: If you spot a friend when he's gambling in a casino, don’t go and touch him on the shoulder—he might punch you back. It's bad luck. Counting Money: Counting money while gambling is not only unlucky, it also looks dumb. Periodic Win: It's a common superstition that women are more likely to win when they are having their periods. Lights On: When going out to gamble, leave all the lights on at home. I don't know whether it attracts luck, but might save you from thieves. Nuns and Monks: Avoid seeing monks or nuns on your way to gambling. It seems gambling and spirituality don’t like each other much. Peacock Feathers: If, for some reason, you carry a peacock feather on your person, ditch it before entering a casino. Main Doors: Casinos usually have impressive main entrances, but gamblers think it's unlucky to enter a casino from the main door. Sneak in via a side route. Bad Days: Friday the 13th is unlucky in the UK, but in Spain it's Tuesday the 13th. Lady Luck probably has a day off when these days coincide with number 13, although it seems her schedule is different for different countries. Knock on Wood: Knocking on wood is supposed to release ancient spirits that reside in trees. Many gamblers might not know that, but would still knock on wood before putting their bets. Broken Mirror: If you broke your side-view mirror while driving to the casino, or just broke any mirror, don't gamble on that day. Gambling superstitions go on and on, but I stopped at 18 because, as you know it now, the number is supposed to be lucky. Happy gambling!