In Denmark's New Year's Eve tradition, old plates are traditionally smashed against friends' doors for luck.
The custom involves saving unwanted or chipped crockery and throwing it against the outside of a friend's home at New Year. A large pile of broken plates was traditionally interpreted as a sign that the household had many loyal friends willing to visit and celebrate. It was therefore more about social goodwill than hostility toward the occupants.
The practice is often associated with Denmark's broader collection of noisy and playful New Year's customs. Modern celebrations may use fewer breakable objects because of cleanup, safety, and changing household habits, but the image of crockery outside a doorway remains a familiar Danish New Year symbol.
This tradition should not be confused with the use of fireworks, which are also common in Denmark. Danish New Year's food and customs vary by family and region, so not every household participates in plate-smashing.