By the way, it's not official because I didn't want to promote heavy drinking, but the way my friends and I play is that if you lose the game, you have to finish your beer. Feel free to play that way or not. Drink responsibly.
Here's my variant for the "Defeating the wizard" rule.
When you win, no one drinks until you roll.
Roll 1d6
1 - The wizard defeats you, keeps the treasure, and sends you back to the dungeon. You have to finish your beer as if you lost the game along with your friends.
2 - The wizard defeats you and keeps the treasure. You have to take a drink to nurse your wounds but you're not sent back to the dungeon to take the long, sorrowful drink with your friends.
3 - You chicken out. You hand the treasure over to the wizard and carry on. Nothing happens to you but your friends have to finish their beers (the basic rules style of winning the game).
4 - You don't win but your bravery earns the wizard's respect. Nothing happens to you and you get to choose one person to be teleported out of the dungeon. Everyone else has to finish their beers.
5 - You narrowly defeat the wizard. Your friends are returned from the dungeon and everyone raises their drink and toasts your victory.
6 - Ultimate victory. You defeat the wizard. Your friends are returned from the dungeon but they all finish their beers as a tribute to your greatness. Then you go around the table and everyone needs to say something nice about you.