Scooby Doo Mystery ages 5 and up I made up a picture or map of my backyard on the computer (you can draw one too) with X s placed in several locations I then cut the map into pieces equal to the number of invitations sent out. (keep an extra copy of the map and pieces in case someone forgets theirs)  Everyone is told to bring the map piece to help solve the mystery. When everyone showed up we placed their puzzle pieces together on the table.  I recounted a tale of how the cake I had made had vanished and I was so upset.  Perhaps the clues could help us find out who took the cake. (you can relate whatever mystery you wish to get the kids inspired to solve it) I used the extra puzzle pieces I kept for anyone who didn't show up or forgot.   We then sent the children out to find the clues.  I had prearranged with a neighbor or parent who was present at the party to wear a certain color, have yarn or string in their hair and have a muddy footprint from a pair of their shoes stamped onto a piece of paper.  The clues hidden in my backyard were (1) a color of construction paper (2) piece of yarn (3) piece of paper with muddy footprint--related to what the "suspect" was wearing.  The children worked together to figure out who was the culprit.  I had one younger little girl who was upset with the person who took the cake, so make sure the children are older and understand it is only a game. Everyone else had a great time and the adults laughed when the "suspect" mentioned "I could have had the whole cake if it wasn't for those meddling kids!"