MTV’s The Challenge pits reality stars against each other in multiple physically demanding mini games. It’s become more difficult for contestants since its debut in 1999, so much so that Bill Simmons has called the show “America’s fifth major sport.” The series requires more skill and athletic ability with each season that passes, leading to intense matchups and elimination moments between competitors.

For Season 35, the brand leaned into the competitive aspect of the reality series both with the framing and formatting of the show. For the first time ever, the franchise introduced red skull trophies into the competition, which the contestants would only earn if they won an elimination matchup and having one was the only possible way they would be able to take part in the final to win the $1 million prize. It was a twist no fan or competitor was expecting.

“The Challenge is all about athleticism and performance and winning, so we looked at the previous few seasons, which we do every season, and said, ‘What worked? What didn’t?,” Harkin told Variety in discussing the addition of red skulls. “The overarching thing we realized was people really have to be forced to perform here.”

The post-apocalyptic theme also upped the need to perform on the part of the 28 contestants. It was an immersive setting in which the stars were living in a bunker without connection to the outside world. The first challenge required each person to pull a barrel with medical supplies 500 feet across a field while host TJ Lavin drove a tank across the field and occasionally destroyed their progress, and the gameplay only became more intense as the season continued.