Trick or Treat

Trick-or-treating is a customary celebration for children on Halloween. Children go in costume from house to house, asking for treats such as candy or sometimes money, with the question "Trick or treat?". The word "trick" refers to a (mostly idle) "threat" to perform mischief on the homeowners or their property if no treat is given. In this custom the child performs some sort of trick, i.e. sings a song or tells a ghost story, to earn their treats. 

Because the holiday comes in the wake of the annual apple harvest, candy apples (known as toffee apples outside North America), caramel or taffy apples are common Halloween treats made by rolling whole apples in a sticky sugar syrup, sometimes folloewd by rolling them in nuts.