One fun Halloween game that I've played with friends for years is a Horror movie trivia game. We play for candy. (It isn't Halloween without treats.)
It works best with 3 or more people.
A Bucket, Hat, or Bowl (to put the questions in)
Paper torn into smaller pieces
Pens and or pencils
Bells to ring in when you know the answer to someone else's question
Small prize for each question that is answered correctly (candy, pennies, etc)
The way we play is fairly simple. We each write out a bunch of questions on separate slips of paper and put them all in a Halloween bucket. Then we take turns pulling out a question. If the person who drew the question out doesn't know the answer, someone can use their hand bell to ring in and snag the other person's candy. This game is great to play with any type of movie, and I've been known to play it with my family during power outages.
The best games are ones you can play anywhere.