Rip off little kids! :D

If you're in the US, the tradition is to go "trick-or-treat"ing. Mostly kids & some teenagers do this. You dress up as a character from a movie/anime/tv show/etc. or anything/anybody you want to be then drive around a neighborhood and go from house to house, knocking on the front door. I should note that you don't do this alone, people generally go in groups from house to house. When someone comes to the door, you say "trick-or-treat"! Then, the person who answered the door will give you some candy. All you have to do is hold a bag out in front of you. If you're older (late teens and older), you're a little too old to go trick-or-treating. People in this category typically either go to a Halloween themed party or stay home and greet trick-or-treaters with candy. There are also places to go like haunted houses, etc.