Trick-or-treating declined in the late 1970s and early 1980s because of the tainted candy scare that warned of poison and razor blades in distributed treats. Hospitals got involved, offering free X-rays of Halloween candy. The scare was an urban legend that has been debunked to the return of trick-or-treating.
The concept of trick-or-treating probably dates back to the early All Souls' Day parades in England. During the festivities, poor citizens would beg for food and families would give them pastries called "soul cakes" in return for their promise to pray for the family's dead relatives. The distribution of soul cakes was encouraged by the church as a way to replace the ancient practice of leaving food and wine for the returning spirits on Halloween night. The practice, which was referred to as "going-a-souling" was eventually taken up by children who would visit the houses in their neighborhood and be given ale, food, and money.
The tradition of dressing in costumes and masks on Halloween finds its roots in both European and Celtic history. On Halloween, when it was believed that ghosts came back to the earthly realm, people thought they would encounter the ghosts if they left their homes. Therefore, to avoid being seen by these ghosts, people would wear masks when they left their homes after dark so that the ghosts would mistake them for fellow spirits.
In North America, the practice of trick-or-treating dates to the late 1920s.
Candy should be wrapped. In general due to safety issues, children are not allowed to eat candy from people they don't know that isn't still in the original manufacturer's sealed containers, or appears unwrapped.
Candy corn, considered one of the icons of the Halloween celebration, is a popular treat.
Instead of candy, you can give out "party favor" type items. For instance, in some places you can buy packages of small Play-Doh containers—each only costs 20-30 cents. Many stores sell Halloween themed party favors, like plastic yo-yos or small bouncy balls or vampire teeth.
If no treats are received, the visitors may try to pull pranks on the people's houses to trick them. Well-known pranks include toilet-papering and egging, both of which are forms of vandalism.
Would-be tricksters should keep in mind that egging a person's house or car can cause permanent damage to the paint job if not taken care of immediately, with a belief that it can cause more harm in colder environments due to the freezing effect. As eggs are organic, it will also leave a rotting smell as the egg decays over time.
Some homeowners use an alternate interpretation of the phrase "trick-or-treat", choosing the trick option, which is not traditionally implied as an option for the homeowners. They will then perform a magic trick for the trick-or-treaters.