If a customer's behavior changes noticeably for the worse after several drinks, the server should:

A noticeable change for the worse in a customer's behavior after several drinks — becoming louder, clumsier, more argumentative, or unusually withdrawn — is a cue that the customer is becoming intoxicated and that the server should slow or stop alcohol service and monitor them. Behavioral change over time is one of the clearest indicators of rising impairment, often appearing alongside physical signs. Responding to these cues promptly, rather than waiting for severe intoxication, makes intervention easier and helps prevent harm. Attentive monitoring of behavior is central to responsible service.