Wild Wasteland

 is a trait which only appears in Fallout: New Vegas.

Wild Wasteland unleashes the most bizarre and silly elements of post-apocalyptic America. Not for the faint of heart or the serious of temperament.

In an interview with Chris Avellone, he notes that the Wild Wasteland trait may add more references to older content in Fallout and Fallout 2, in regards to special encounters. Players without Wild Wasteland will find less silly analogues in places where Wild Wasteland modifies things. According to JE Sawyer the trait was added as a compromise because different members of the team often suggested 'wacky' content that others thought would be out of place.