“Plus, in a world where dark wizards are kidnapping or killing people on a regular basis, a little under-age drinking is the least of their problems.”

Overseas audiences may respond differently to the drinking scenes. In England, the legal drinking age is 18, but 16-year-olds can order alcohol if they’re eating a meal. (Even by those standards, the teenagers in the movie were flouting the law: during the pub scene, no food was served.)

Alcohol educators say that they don’t want to ruin the fun, but that parents should be aware of alcohol’s role in the Harry Potter series, the books as well as the movies. Several studies suggest that movies influence teenagers’ behavior when it comes to drinking, drugs and tobacco. An Institute of Medicine committee on under-age drinking has said there is “a strong possibility” that youth exposure to alcohol through movies contributes to early initiation of alcohol use.

A 2007 study of nearly 5,600 German teenagers looked at the relationship between drinking activity and exposure to American movies. Even accounting for variables like friends’ drinking habits, the researchers found that children with high exposure to alcohol in movies were nearly three times as likely to binge-drink as those with the lowest exposure.

Similarly, a study of 3,000 adolescents found that those who were most often exposed to smoking in movies were nearly three times as likely as others to try smoking. In a striking finding, the study concluded that in more than half the times that a child in the study tried a cigarette, the decision was linked to having seen smoking in a movie.

Alcohol experts say this does not mean that children shouldn’t see the new Harry Potter movie. It actually presents an opportunity for parents to talk to their children about alcohol, says Dr. Christopher Welsh, a University of Maryland psychiatrist and addiction specialist.

“I hope parents can talk to their kids and tell them even though Harry Potter made that seem fun, that it isn’t O.K.,” said Dr. Welsh, the author of a 2007 article about alcohol use in the Harry Potter series, published in The Journal of Child and Adolescent Substance Abuse.