Alcohol of various forms has been associated with characters throughout the Lost storyline. Sometimes the effects of alcohol have led to the revealing of interesting plot points, such as the fail-safe discussion and Christian's attempt to visit his daughter.
When Locke and Cooper met for the first time, Cooper said, "Something tells me I'm going to want a drink for this" and then offered Locke a scotch. ("Deus Ex Machina")
Jack and his father drank vodka at the hotel pool where Jack was trying to write his wedding vows. ("Do No Harm")
After murdering her father, Kate visited and ordered a beer from her mother, who worked as a waitress at Keith's Diner. She refused to serve it to her. ("What Kate Did")
Kate and Cassidy shared a drink at a bar in Iowa while talking about Kate's purposes to meet her mother and Sawyer's role in Cassidy's life. ("Left Behind")
Jacob used a wine bottle to explain the character of the man in Black and the Island to Richard. Jacob offered this same bottle later to the MiB who destroyed it. It may have been the same bottle used in the ritual centuries before. ("Ab Aeterno")
Jack found a small bottle of vodka in his pocket upon regaining consciousness in the pilot episode and used it to sterilize his wound when Kate sewed it up. ("Pilot, Part 1")
Sawyer and Kate played a game of "I never" with 2 bottles of spirits Sawyer stole from the plane wreckage. One of these bottles was of J. Darby whiskey, the same bourbon Desmond drinks in the hatch and on his boat. ("Outlaws")
Sawyer gave Kate his entire stash of alcohol, which she attempted to bring to Jack in his efforts to save Boone. She fell and smashed some of the bottles inside her backpack. ("Do No Harm")
Juliet drank a bottle of DHARMA rum after the Freighter explodes (this is actually a real-life bottle of Mount Gay Rum relabeled indicating that The DHARMA Initiative did not supply their employees with cheap liquor). ("There's No Place Like Home, Part 2")
Horace is caught on camera by Phil and Jerry intoxicated and trying to blow up trees with dynamite. ("LaFleur")
Post-Island[]
Jack tried to order another drink, while already visibly intoxicated, from a flight attendant two years after the crash. ("Through the Looking Glass, Part 2")
Jack poured himself a screwdriver (orange juice with vodka) whilst watching Hurley's car chase on TV. ("The Beginning of the End")
Drinking games involve drinking a pre-determined amount of alcoholic beverage whenever a pre-established condition has been met. The objective is to win via others becoming too drunk to continue participating, or sometimes to simply increase the enjoyment of the related activity through inebriation. In the fandom of Lost, one such drinking game is called "Jackface" based on the expressive and varied facial expressions of Matthew Fox; another example is drinking whenever Hurley says the word "Dude."