Four famous characters - Max (Sam & Max game series), RED Heavy (Team Fortress 2 game), Tycho (Penny Arcade webcomic), and Strong Bad (Homestar Runner web series) - just sit around a table in the underground casino called Inventory and play poker. According to its owner, it is hidden under a video game store and is kept secret so that if the government outlaws gambling one day, it will know nothing of Inventory. The player does not control any of the characters but is instead an invisible character on its own, who is literally referred to as The Player by other characters.
All players have a reserve of $10,000 at the beginning and leave the game if they're left nothing to put at stake. The ultimate goal for the player is to remain the last one sitting behind the table. Sometimes the opponents will put their recognizable belongings, such as Heavy's iconic bazooka Iron Curtain, at stake. This is essentially a board game, however, funny animation and characters' chit-chat filled with references and jokes may keep one interested.
Achievements in Poker Night at the Inventory allow unblocking certain special features in Team Fortress 2.