When you host a party, you could be held legally responsible for the actions of guests who drink at your house. It can be pretty complicated depending on the situation, but the bottom line is that if you have a party where alcohol is available and someone who's been drinking injures or kills him or herself or another person, you can be sued. Being sued can be costly to you and your parents. Even if nobody gets hurt, when things get out of hand there is also the cost of replacing damaged or stolen property—not to mention that we are talking about the safety of your friends.