On campus, safety comes first and discipline comes much, much later. Students feel that campus police are not very strict and only enforce rules if you make your violation particularly obvious or create an infraction that puts students in danger. The situation with RAs tends to be the same. If you walk into your RA's room with a bottle of alcohol in your hand, you will most likely get written up, but if you keep it in a room with the door closed, the chances of getting in trouble are very low. The official alcohol policy at Penn says that "in cases of intoxication and/or alcohol poisoning, the primary concern is the health and safety of the individual(s) involved . . . . No student seeking medical treatment for an alcohol or other drug-related overdose will be subject to University discipline . . . . This policy shall extend to another student seeking help for the intoxicated student."
Fraternities and sororities probably get cited for alcohol violations more than any other group, but while the organization can be placed on probation, specific students are not usually held responsible. Spring Fling is the time when security is the most strict, and all guests are required to register for passes and stay with the person they are visiting at all times. However, even at this time, security tends to be spotty, and often security guards let people they recognize slip by because they are bombarded with more visitors than they can handle. Overall, the school is not strict about many things.