My rating system is sort of strange because I can totally love a book and still give it "only" 3 stars mostly because my ratings are based on the following criteria.
★ Story - Original, strong/coherent plot and a satisfactory ending.
★ Characterisation* - Memorable characters with distinct voices.
★ World Building - Complex, consistent, imaginative and seamless integration.
★ Compelling - Engaging with a strong desire to find out what happens next.
★ Writing - Use of language, strong/confident narration, effective style.
* Characters don't necessarily need to be likable, but they do need to be interesting.
If it's obvious a copy editor and proofreader were not consulted, the book usually ends up in the rubbish bin.
If I can't force myself to finish a book because it is sorely lacking in the above criteria, I will place it on my DNF shelf without a rating.
Sometimes I am not in the mood for a certain book, sometimes a book might need a little more attention than I can give it, etc. When this happens I will place the book under the Reconsider shelf, but not because it was absolute crap, but as a reminder that I felt it was good enough to try to re-read in the future.
Stereotypes, cliches, excessive use of plot devices, and blatant foreshadowing are a no-no.
I abhor rolling my eyes and if it can be avoided, I am extremely grateful. If a book makes me do this once, half a star is gone. Repeatedly? The book might end up with just 1 star.
Other reasons for a 1 star rating will most likely be listed as part of my written review of the book. 1 stars are a rarity, almost as rare as a 5 star, and I almost feel bad about finishing terrible books because of this.
Easier to understand rating chart:
★★★★★ - Everything was perfect!
★★★★ - Highly entertaining~ couldn't put it down.
★★★ - Enjoyed reading and would recommend to others.
★★ - Good enough to finish reading.
★ - Waste of time, so terrible I would not recommend it.