Although it is evident who is invited, you should still send out invites to your employees and even a close friend or spouse. To set the secretive mood, address two separate envelopes to each person that is invited, even if the couple is married.
Explain that the guests is a suspect and the character that they are to play and suggest what to wear in addition to the relationship that this character has in relationship with other characters. Also explain what kind of costume should be worn. Let your guests know what to expect as well.
As far as decorations, try and go for a Clue theme. You can ask your employees for props or dig up decorations from Halloween to bring a mysterious and creepy mood. Greet your guests at the door with a name tag and perhaps little notes about their character. Have unique corporate gifts on a table to reward your employees at the end of the night.
You should know that there are mystery dinner kits available online and in your local stores and require specific directions for each clue or a different setting for each clue.
As far as dinner, you should base the number of courses for your meal on the number of scenes in your murder mystery. Clues can be discussed while you eat. However some mystery kits are designed for cocktail parties and guests are expected to walk around and interact with each guest.
Have two guests work together to make sure the evening's events are in order. As for the dinner menu, go with simple foods that can be easily catered from the company's favorite restaurant.
During dinner sporadically reveal clues to the guests and have them spend fifteen minutes per scene so that they are able to get the necessary information. The mystery dinner should last 2 ½ hours but if you linger over cocktails, food and desert; the party can go all night if you wish. Remember to have your guests stay in character until the mystery is solved, this makes things more enjoyable.
Give your guests a padfolio to record their clues and they can also keep their padfolios as a souvenir. Many of these plots take place in different countries or time periods depending on the mystery kit that is purchased. This should make dinner and decorating a little easier if you go with a mystery kit. You can also download a murder mystery online as well.
Normally while guests are eating, each meal is associated with a clue. As mentioned before if you don't come across a mystery dinner kit that you like, create your own and be creative with the food. You can also have music to go along with each scene by using a computer or an iPod.
Having a murder mystery dinner will give employees a chance to know each other better, old or new. This will also give them a chance to display teamwork and strengthen the bond between employees. By having a mystery dinner for your employees it will not only show that you are about them and you want them to relax, it also shows that you value their loyalty. Once the criminal is caught at the end of the dinner, it is a good idea to reward the winner with a corporate gift basket.