The duel is an old game where you do a challenge and the 2 with the worst scores face off with another challenge, where the one with the worst score on the 1v1 gets evicted.
BioDork put it like that when he went crazy.
It was a game once and then rando took it away cause it was too much fun for the website to handle and the servers got jammed. Then the people revolted because they loved and missed the duel and hacked into the game. Randomize banned them all and kicked them out of the game but left The Duel sitting on the games page as a reminder to all that if you do not follow the rules you will be exiled.
Temeky has it wrong. Biodork went crazy because of the lack of dueling possibilities and the unjust treatment of the hackers, but he never hacked the game himself, he just abused his mod powers.