The Devil tarot card in the Major Arcana represents unhealthy obsessions, addictions, attachments, as well as indulgences. This is the card that represents everything to do with physical pleasures. This is the card that represents pure materialism, enslavement, and bondage. It also represents temptation. However, one positive thing that the Devil does represent is commitment. And that is not surprising since attachment is what this card represents as well. Therefore, being committed results in being attached.
However, the fact of the matter is, whenever this card comes up, it warns the querent that they are becoming unhealthily attached to an idea, to someone, or something. You may be picturing someone who is going to a buffet and indulging themselves represented by the Devil. That is not necessarily the case. Especially if it is a one-time thing. Remember, everyone has to celebrate and let loose.
The Devil is only accurate when it comes to this type of scenario if someone who has a food addiction is heading to the buffet night after night. That is an unhealthy attachment to a physical pleasure, which is again, an addiction. A false need.
If we take that example of the high school student, you could say he started smoking. It does not matter if it was the result of peer pressure. However, he got into the bad habit and now he is stuck with it until he finds a way to quit, which he is not ready to do.
When the Devil is in reverse, it can be a positive thing because it represents breaking free from unhealthy attachments and addictions. It can also represent divorce which in some cases is a positive thing if the marriage was unhealthy from the start.
Astrologically this card is tied to Capricorn and it is the 15th card of the tarot deck. The Enneagram type this card is associated with is type 6.