What is the origin of the idiom "play hard to get" and when to use it?

The idiom "play hard to get" originates from the world of dating and relationships. It is based on the observation that people are often more attracted to those who seem less available or not as interested. It is used to refer to someone who adopts a deliberate approach of appearing uninterested or less accessible to someone who is expressing romantic or sexual interest. This strategy aims to create an element of challenge or pursuit, with the belief that it can increase the other person's desire or interest.