Designated Drunk
Responsible partiers choose a Designated Driver to drive during a night of debauchery. The Designated Drunk is chosen by the Driver.

The Designated Drunk assumes responsibility for all drink offers given to the Driver. The Designated Drunk will take all offers of toasts, shots, and drinking competitions in place of the Driver.
Random drunk: "Hey dude! Come have a shot with me!" 
Designated Driver: "Gary, you're DD. Take that shot for me."
Gary: "Alright."