mass draft
when one person from a group of people is sent to the bar to buy multiple beers so as to avoid everyone having to tip on their own purchase. once money has been gathered from everyone, the person chosen as the mass drafter buys everyone's beer and then tips just as if he had only bought a beer for himself. the person required to mass draft is usually rotated throughout the night.
Hey Jim, we all want some beers and it's your turn to mass draft. Make sure you tip the bartender.