The Liquor on the Table
The liquor on the table is a meta-technique made to signal to players that they should intensify their play, without disturbing the game.
It's as simple as it sounds. Putting a bottle (or more) of liquor on the table signals to the players that the characters are getting more drunk, whether or not they are drinking real alcohol, and it's time to take out the last of the conflicts and intrigues that have been building up throughout the game.
For games with a planned dramaturgical curve where the setting is a social scene that includes alcohol, this gives the players a hint that the game is nearing it's end and it's time to bring out the last of the juice. Other things than liquor can of course be used, the main function is for the players to know when to intensify their play.