Vadding is a verb which has become synonymous with urban exploration. The origin of the word comes from MIT where, for a time in the late 1970s, some of the student population was helplessly addicted to a computer game called ADVENT. In an attempt to hide the game executable from system administrators who would delete it if found, the file was initially renamed ADV. As the system administrators became aware of this, the filename was changed again, this time to the permutation VAD. The verb vad appeared, meaning to play the game. Likewise, vadders were people who spent a lot of time playing the game. An urban explorer stands near the outfall of a muffin shaped brick and concrete storm drain, under Saint Paul, Minnesota. ... The Massachusetts Institute of Technology, or MIT, is a research and educational institution located in the city of Cambridge, Massachusetts, USA. MIT is a world leader in science and technology, as well as in many other fields, including management, economics, linguistics, political science, and philosophy. ... Adventure (also known as ADVENT or Colossal Cave) (Crowther & Woods, 1976) was the first computer adventure game. ...

In a bizarre segue, vadding and vadders began to refer to people who undertook actions in real life similar to those in the game. Since ADVENT was all about exploring underground tunnels, the popular MIT geek sport of roof & tunnel hacking became known as vadding.

Today, the word vadding is rarely heard at MIT, and usually only by old-timers. "Roof and tunnel hacking" has returned as the preferred descriptive term. Those who participate in it generally refer to it simply as "hacking." Vadding and hacking are both terms born out of MIT jargon that, once they left the MIT community, began to mean something entirely different. A mural by Roof & Tunnel Hackers at MIT, 2004 Roof and Tunnel Hacking is the unauthorized (generally prohibited and often outright illegal) entry into and exploration of roof and utility tunnel spaces. ... Look up hacking in Wiktionary, the free dictionary New York street sign, c. ...

See also

• Elevator surfing