Old plates are the household items traditionally thrown at friends' doors on New Year's Eve in Denmark.
The custom involves saving unwanted crockery and breaking it against the doors of friends or neighbors around New Year's Eve. The act is meant as a sign of affection and friendship rather than vandalism. A large pile of broken plates traditionally indicates that a household has many friends.
Modern Danish celebrations also commonly include a festive dinner, fireworks, champagne, and the midnight singing of “Vær velkommen, Herrens år.” Another familiar custom is jumping from a chair at midnight, symbolically leaping into the new year.
Descriptions of the plate tradition vary by household and region, and it is less universal today than its popular image suggests. The important cultural point is that broken crockery historically represented social bonds, not a hostile act.