Last week was Friday the 13th, so we asked our readers to tell us if they have any superstitions or rituals they do for luck. Here are their answers ...
1. Don't step on that book!
I'm from Nepal, and there's a tradition there that the goddess of knowledge, Saraswathi Maatha, lives in all books and paper. So, if you step on either, it's said that the goddess will not bless you unless you ask for forgiveness. So, many Nepalese touch things they've stepped on, then touch their foreheads to ask for forgiveness.
Limbu Laxmi, 17, Delia Memorial School
2. Throw your worries away
I always write down my worries or things that pressure me on a piece of paper, then throw it away. Afterwards, I feel like a weight on my shoulders has just disappeared.
Sharon Lee, 17, St Paul's Convent School
3. Out with old errors
I buy a whole new set of stationery before exams. I believe that if I use my old one, I'll make the same mistakes again. But I don't buy new erasers, as they might help me to correct new mistakes.
Winnie Yip, 16, Li Po Chun United World College
4. That 'I'm smarter' feel
It's a bit silly, but I always have to wear my glasses rather than my contacts when I'm sitting an exam. I don't know if it's because it makes me feel smarter or just more confident. Either way, I tend to do relatively better (I think).
Wincy Leung, 17, King George V School
5. The cocoa factor
Eating chocolate before exams! My mum firmly believes that the cocoa component helps with thinking, and I believe it, too. Now every time before tests, I munch on some dark, milk or peanut (you name it) chocolate. I'm not sure if the theory can be proved scientifically, but it gives me an excuse to eat chocolate once in a while.
Minnie Yip, 16, Diocesan Girls' School
6. Laugh-cry yin-yang
There's a saying I truly believe in: "If you laugh now, you will cry later." Therefore, I tend not to laugh too much. Also, if I have an important event the next day, I'll watch sad movies to force myself to cry.
Anna Rai, 16, St Margaret's Girls' College
7. No pre-exam eggs
When it comes to exams, I am very superstitious. I never eat anything that's dark-coloured before an exam, nor do I eat eggs because they're the same shape as a zero. I always hold my books and notes, and never place them on the floor. Also, I have a certain way of putting my stationery around my desk during an exam. I wear a particular clover necklace and I even have a special hair tie for the occasion.
Michele Chan, 14, Wycombe Abbey School (Britain)
8. Scarred only, please
Superstitions are rife in my life. I won't use a device until it's been in one accident that has left its mark. My phone and iPad bear battle scars from brawls with the pavement, and the glass is cracked on both. My laptop case is scratched and dented, and the metal itself is all dinged up, but it's still perfectly functional.
Another superstition: I won't walk under plants indoors. Potted palm fronds scare me; they feel like fingers. The story of Baldr's death, by a mistletoe-branch dart, frightens me, too.
Meaghan T'ao, 18, Dana Hall School (US)
9. Blanket security
If I sleep with my blanket upside down, I feel that something bad is going to happen. I tried to fight this superstition once by forcing myself to sleep with the blanket the right way up. It got into my head; I couldn't fall asleep for three hours.
Olivia Lam, 15, St Paul's Convent School
10. Pass the spearmint - before 6pm
There's one from Turkey I find particularly fascinating. Locals believe that chewing gum at night is similar to "chowing down on the flesh of a dead person". If you go to Turkey, don't chew gum at night!