Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
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Many believe that if all of the candles on a birthday cake are blown out with one breath, while making a silent wish, the wish will come true.
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When you speak of bad luck, it is said that one should always knock on wood. Also knocking when speaking of good luck apparently helps with having good luck. This is an old Celtic tradition related to belief of wood spirits.
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According to an age old custom, carrying a dead shrew in your pocket wards off rheumatism!
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It's bad luck to leave a house through a different door than the one used to come into it.
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It is bad luck to put new shoes on a bed (or a table) (comes from the tradition of dressing a corpse in new clothes and shoes and laying them out so everyone can give their respects) - (UK)
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Before traveling a person should, apparently, sit on their luggage. (Russian)
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Placing keys on a table is considered unlucky. (Sweden)
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