A competition in which multiple teams of 3 members each compete to see which team can consume a 30 pack of beer, 3 grams of marijuana and a sheet pizza first. This competition is so called because after about an hour after the competition has begun, all teams are so high, drunk and full of pizza that nobody cares about who wins and just end up enjoying each others' company. As gentlemen (and gentlewomen) do.
Philip: "I must say, William. The participants of this year's Gentleman's Challenge are really in the spirit of the competition."
William: "Indeed, sir. It appears no one has given a single fuck about winning since the third blunt was rolled."