This comes as a recurring afterthought, something I kept thinking to tell people in general and potential clients in particular. It should make a good addition to Why Magic Fails, but it solely focuses on cases where the force you've set into motion is powerful, the ritual was done using a good election, etc. It applies to beneficial spells too, but by shifting perspectives, although I've spoken of spells in general in Words.
In order for a curse to work completely as intended, it must utterly obliterate a certain structure or structures. That is to say, it must destroy a construction that is more or less material in nature, but is the product of our material existence nonetheless. It can be someone's body, relationship, status and so on. Cracking that structure is not enough, for it will simply cause more or less damage one can overcome more or less easily.
That's why a lot of curses have only temporary, often short lived outcomes, especially if the curses themselves aren't permanent. In "A living hell: The eerie twelfth house" from Asteria 2 I briefly mentioned permanent curses saying they're not a topic for that book. Perhaps I'll write a class on the matter at some point. We shall see although there's no actual need since I already have a class on that's covering one particular powerful kind of such curses.
