Things You'll Need
Classic practical jokes are like anchovies: people either love them or hate them, but there's no middle ground. One of the oldest, simplest pranks is the bucket booby trap. You've seen it in a thousand different movies and TV shows: An unwary person strolls innocently through a doorway, only to be drenched or covered by the contents of the bucket. The bucket door trick is as simple to set up as it is to enjoy; just make sure you know who is going to be first through that door.
Fill a plastic bucket with confetti, small bells or any other lightweight, non-harmful substance. You can also use water, if you are an adult and are responsible for cleaning up your own messes.
Open the door about as wide as half the diameter of the bucket.
Balance the bucket with its bottom on top of the door. Use the step stool to reach it, if you have to. Make sure that the bucket is slightly off-balance and leaning on the top of the door jamb. If you just balance it on the door, you can't necessarily control which way it falls.
Stand back and wait -- the first person through the door is in for quite a surprise.
Have an escape route in mind, in case the first person through the door is not a fan of practical jokes.
Never use a galvanized bucket or anything else heavy.