Good Cop/Bad Cop is a psychological tactic, often used by police for interrogation.

Two 'cops' alternate their interviews. The 'Bad Cop' behaves negatively toward the subject, making blatant accusations, derogatory comments, threats, and in general raising the subject's antipathy. This sets the stage for the 'Good Cop' to deceptively act supportive, understanding, defensive, and in general show sympathy for the subject, which may make the subject cooperative towards the latter.

The technique is easily recognized by those that are familiar with it, but it continues to work on the majority of subjects that are young, frightened, or naïve. It is important to properly assess the subject's level of intelligence and experience with the technique prior to its application. The technique is often seen as offensive and insulting to those that recognize it. This may make the subject refuse to cooperate outright, where a more advanced technique such as the Reid technique might yield results.