A party involving many or one keg. Either can be a party with admission (everyone pays per cup or at the door for a bracelet) or a free party put on my a host who buys it
A party in which ketamine, ecstasy and GHB, K-E-G, are available instead of alcohol. The term is used in conversation around those not in the know about what kind of party you are really talking about.
"I'm gonna get goofed up, roofed up and drop inside a dark black hole at the KEG party!"
An situation which is generally in MMO/RPG's where the gameplay is based on the consumption of Health/Mana/Status of your Choice potions or the players find themselves with an excess collection of potions to the point where they could hold a Keg Party, invite all their mates and imitate a Beer Keg Party.
"I got so many Health Potionsleft over we could throw a Potion Keg Party, invite our entire guild and get wasted!"