My birthday party was unique, in our town at least!  I Had a Murder Mystery Dinner Party.  My Mom said it was the cheapest party I'd ever had!  All you need is a mystery set/box.  It has everything you need in it. You can buy them off of the internet for about $20.  I gave out the invites about two weeks before the actual date so that everyone had time to find or buy their costume.  Each set takes about 3 hours to do. My party was from 6:00 til 10:00. It is better to have your party on a Friday or Saturday so you can stay up later.  MAKE SURE NO-ONE IS LATE. Everyone will sit at a big table for your dinner.  The whole story unfolds at the table. Everyone is given a character booklet which has their background and their script inside. Aswell as the script there is often somw acting to do. There is usually a cassette tape with a narrator to start you off. The game is split into rounds with a break for a course of your meal after each one. The murderer is told who they are on the last page of the booklet but they are not to let out otherwise it spoils the game. After all the rounds are finished you go round the table and everyone says who they think the murderer is. The person who guesses correctly is the winner.  I made my party 4 hours long so we had time to open presents and cut the cake and sing happy birthday, OF COURSE! I recommend this party for either girls only or girls and boys.  Girls may enjoy dressing up as boys, but boys, I am sura will not enjoy dressing up as girls! 12+ year olds is the best age for this sort of party, although you do get different sets for different age groups.  Younger ones are not murders and adult ones are alot more complicated. Have Fun !!!!!