From the Kickstarter campaign:
Each backer will receive an exclusive DrunkQuest shot glass. For months now we've developed a house rule for our play sessions. At any time when a player has to take 14+ drinks they may instead opt to take a shot. The shot is full of whatever the owner of the game decides, and it sits on the table...waiting. Now you, the owner of DrunkQuest may use our house rule as your own. Feeling generous one night? fill the glass with a nice lemon drop shooter. Feeling vindictive? Jagermeister it is.
These shot glasses don't have rules included or have any markings to denote 14 shots. Players can use any shot glass to implement the optional rule. It's not necessary to have these specific glasses.