Placing keys on a table is considered unlucky. (Sweden)
3
It's bad luck to leave a house through a different door than the one used to come into it.
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If you catch a falling leaf on the first day of autumn you will not catch a cold all winter.
394
An acorn at the window will keep lightning out
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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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Placing a hat on the bed is, apparently, bad luck. (South Carolina)
9
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.
70
Pirates believed that piercing the ears with such precious metals as silver and gold improved one's eyesight.
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