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.
105
Breaking a mirror is said to bring bad luck for 7 years. To "undo" this, take the shards of glass and bury them underneath the moonlight. In ancient times, the mirror was said to be a window to the viewer's soul. If that mirror were to break, it would
123
The superstitious symbolism of a black cat crossing one's path is dependent upon culture: some cultures consider this a sign of impending bad luck, while some cultures consider this a sign of impending good luck.
75
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.
208
Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
225
Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
117
In Asia, the digit 4 never appears in any Nokia handset model number, because 4 is considered unlucky in many parts of Southeast/East Asia.
78
Before traveling a person should, apparently, sit on their luggage. (Russian)
117