Depends on the story, and IIRC it has shifted with time. But yeah, the general trope is they are stuck in a small vessel, and they offer/are extorted into one or more wishes to free them. Why they are stuck ranges from evil sorcerer trying to enslave them to noble hero stopping their rampage.
![[Astutillo Smeriglia] genie.exe has stopped working](https://programming.dev/pictrs/image/92c8eb97-4206-42fa-9cac-e09e89f83afc.png){kind=link}
Supposedly they are malevolent spirits that sometimes may grant wishes as a reward, not by some compulsion.
Depends on the story, and IIRC it has shifted with time. But yeah, the general trope is they are stuck in a small vessel, and they offer/are extorted into one or more wishes to free them. Why they are stuck ranges from evil sorcerer trying to enslave them to noble hero stopping their rampage.