What is "x-venture"

The short-lived X-Venture adventure race was a feature of ESPN's X-Games. The first event, held in 1995, served as the second Eco-Challenge event after Eco-Challenge Maine. Each X-Venture featured 15 teams. The three-person co-ed teams travelled between 300 and 500 miles. Unlike most U.S.-based events, the X-Venture race was held in stages, allowing any team that completed the stage in less than 24 hours to rest until the next stage began. Any team that was six hours or more behind the lead at the end of a stage would be eliminated from the race.