Here is a really fun game to get you started. There isnt much to it, and unless you decide to put your own spin on it there is no messy suprises here but your guests will not know that!
The idea behind this game is you have a prize (or a forfeit if thats how you want to play) and the person with the “Dirty Diaper” at the end has the prize/forfeit bestowed upon them.
Instructions
Take some Napkins or similar and fold them up like Diapers.
Put something like a little Kiss or a sweet or something inside just one of the diapers.
Hand them to your guests as they come through the door, and ask them to open there diaper.
Explain that one will get a dirty diaper!
When the guest arrives who gets the dirty diaper (the napkin with a kiss/sweet) then either bestow upon them the Gift or the Forfeit!