ADVENT), used to avoid a particular admin's continual search-and-destroy sweeps for the game] n. A leisure-time activity of certain hackers involving the covert exploration of the `secret' parts of large buildings --- basements, roofs, freight elevators, maintenance crawlways, steam tunnels, and the like. A few go so far as to learn locksmithing in order to synthesize vadding keys. The verb is `to vad' (compare phreaking; see also hack, sense 9). This term dates from the late 1970s, before which such activity was simply called `hacking'; the older usage is still prevalent at MIT.The most extreme and dangerous form of vadding is `elevator rodeo', a.k.a. `elevator surfing', a sport played by wrasslin' down a thousand-pound elevator car with a 3-foot piece of string, and then exploiting this mastery in various stimulating ways (such as elevator hopping, shaft exploration, rat-racing, and the ever-popular drop experiments). Kids, don't try this at home! See also hobbit (sense 2).