One of my DD's birthday parties was a "CLUE - Murder Mystery Party." She invited 5 girls over for a sleepover and counting her, they became the 6 characters in the Parkers Brother s' CLUE Game.
Her invitation read:
A MURDER HAS BEEN COMMITTED
YOU HAVE BEEN NAMED AS A PRIME SUSPECT!
YOU ARE HEREBY SUMMONED TO APPEAR
AND HELP SOLVE THIS CRIME
AT DDS 12TH BIRTHDAY MURDER MYSTERY DINNER & SLUMBER PARTY
to be held at the DD Familys Mansion on Such&suchdate
I bought fun little costumy things for each character (Red boa & fancy hat for Miss Scarlet, safari hat & yellow top Col. Mustard, purple hat & glasses for Prof Plum...) I pulled girls' names out of one hat & then a characters' name out of the other. I bought yellow crime scene tape and had it all over the front door and outlined a body (that of Mr. Boddy) on the floor. (I warned my neighbors about this, so they would not think a real crime had been committed and it was the talk of the neighborhood.) I turned rooms in our house into the mansion's rooms - bath became the Conservatory, a bedroom became a billiard room and I put play weapons throughout the rooms.
I had them play the board game one time at the start, so they all understood the rules and then I pulled the 3 cards (murderer, room & weapon). Then, instead of rolling dice and moving the pieces on the board, they would roll dice in turn, but then actually run into the appropriate rooms to announce who they thought did it. When the murderer was correctly announced, I played the police/constable and led the murderer away to jail. They thought that was hysterical. They ended up playing & acting it out about 3 times. And, later in the evening, they watched the 1985 comedy movie CLUE with Tim Curry, Madeline Kahn and Lesley Ann Warren.
If you are having more than 6, you could divide them into teams (3 kids work together as Col. Mustard). The girls are now all close to 17, but they all still talk about that party (along with our Alice in Wonderland Party). We had fun.