Bars and others licensed to sell liquor can be held liable under certain circumstances if they serve obviously intoxicated customers who go out and cause injury. Controversial as it is, that's the law. However, what happens when a drinker becomes inebriated at a private party and causes injury? "Social host liability" laws hold that adults who serve or provide alcohol to minors or persons who are obviously intoxicated can be held liable if the person who was provided alcohol is killed or injured, or kills or injures another person. Old legal reasoning held that it was not the service of alcohol by the homeowner that caused the injury, but rather the consumption by the drinker. In other words the bad choice to keep drinking cut off any liability of the homeowner. Again, controversial as it is, those old rules are slowly changing. As of this writing, two thirds of the states, including New Hampshire and Massachusetts, hold that a person who is injured as a result of a social host's service of alcohol may maintain an action against that host if it can be proven that the service was reckless. In this majoriy of states, a homeowner's service of liquor is reckless if the host consciously disregards a substantial and unjustifiable risk of a high degree of danger. Two sure fire ways to demonstrate such recklessness are to serve underage drinkers, or to directly serve an obviously intoxicated guest. But, establishing liability is not simple. There are many roadblocks. For example, concepts of comparative fault or contributory negligence apply. The person who was drinking has less of a chance in one of these cases due to their own fault in drinking to excess. A court may find that, by comparison, the drinker's negligence was greater than the host, thus shutting off his injury claim. The innocent third party injured by a drinker has a stronger case. This guide involves the civil liability of a social host and is to be distinguished from numerous criminal laws on the subject. For example, many states including New Hampshire and Massachusetts make it a crime to serve underage drinkers. Common sense advice is to encourage guests not to over drink. Legal advice is never to allow underage drinking in the home and to discourage overdrinking by anyone.