Baker 13 is one of the most enduring student traditions at Rice University. At 10 p.m. on the 13th and 31st of every month (26th of months with no 31st), a group of students runs around the entire campus wearing nothing but shaving cream. (This is made possible because of Houston's temperate climate during the schoolyear.) Although the event usually only attracts a small number of students, on Halloween and the last relevant day of the schoolyear (usually April 26th), the event is very large, regularly attracting over 100 students. The event is so named because it begins and ends at Baker College.

The runners go by all the residential colleges and often make shaving cream impressions by rubbing their bodies on windows and doors. College members often throw water on the runners. The runners usually shout the college anti-cheer (e.g. "Sid Rich sucks, death from behind") of the college they are running by. They also shout the Baker 13 cheer, "Join us! Join us!"

Although the students are naked, the event is non-sexual in nature (unlike NOD). Instead the atmosphere of Baker 13 is silly and exuberant. Both Baker 13 and NOD are, however, the subject of controversy with critics condemning their hedonistic characteristics and the encouragement of underage drinking.

The run usually finishes at Valhalla , the graduate student pub on campus. In recent years runners have been given a complimentary soft-drink in lieu of a free beer, due to the aforementioned concerns raised about under-aged drinking. Sometimes the runners continue their run, joined by a Valhalla patron or two who decides to join in on the fun.