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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In some parts of England, rum is used to wash a baby's head for good luck.
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Before traveling a person should, apparently, sit on their luggage. (Russian)
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A single magpie is considered a sign of bad luck. A Guide to the Scientific Knowledge of Things Familiar recites an old proverb concerning the incidence of bad weather when magpies forage alone and a possible scientific explanation for this.
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Placing a hat on the bed is, apparently, bad luck. (South Carolina)
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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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Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
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Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
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