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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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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Placing a hat on the bed is, apparently, bad luck. (South Carolina)
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An acorn at the window will keep lightning out
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If one walks underneath an open ladder it is said to bring bad luck. Sometimes it is said that this can be undone by immediately walking backwards back underneath the ladder.
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Amber beads, worn as a necklace, can protect against illness or cure colds.
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According to an age old custom, carrying a dead shrew in your pocket wards off rheumatism!
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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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