And yet, according to the American Bar Association, if a guest gets food poisoning, is injured at your home or drives drunk after a party, the host could get sued.

It's important for hosts to plan for the unexpected.

"I'm a big proponent of safety," Trigg said. She's a fan of the car service Uber -- which can pick you up based on your smartphone's GPS -- for those over-imbibing. "I like to have it be part of the game, have people drop their keys right away," she said.

Especially, if, like Trigg, you tend to hold cocktail contests.