Placing keys on a table is considered unlucky. (Sweden)
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There are numerous sailors' superstitions, such as: it is considered bad luck for a ship to set sail on a Friday, to bring anything blue aboard, to stick a knife into the deck, to leave a hatch cover upside-down, to say "pig", or to eat walnuts aboard.
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Placing a hat on the bed is, apparently, bad luck. (South Carolina)
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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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It's bad luck to leave a house through a different door than the one used to come into it.
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An acorn should be carried to bring luck and ensure a long life.
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Opening an umbrella indoors is said to result in 21 days of bad luck. Some traditions hold that it is only bad luck if the umbrella is placed over the head of someone while indoors.
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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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