The character development is so sequential. Emilia in book one is reactive and grieving. In book two, she's calculating and learning power. In book three, she's commanding and resolving. You can't appreciate her arc without seeing each stage. The book order is the blueprint for her transformation.
I see a lot of people asking this, and the answer hasn't changed. It's a trilogy. One, two, three. 'Kingdom of the Wicked'. 'Kingdom of the Cursed'. 'Kingdom of the Feared'. Anything else is supplementary. The novella 'Throne of the Fallen' is a separate story with different main characters, though set in the same universe. You can technically read it anytime after the trilogy, but it's not required to understand Emilia's journey. Why is this so confusing? Maybe the similar titles? But really, just look at the numbers on the spines or in the series description online.
I've seen this pop up in 'Romantasy' TikTok guides, and they always list it as a trilogy in order. It's considered a staple in the genre now. The reason it works so well is because of that tight, three-book structure. There's no filler. Every book advances the core plot and relationship. So reading them in order gives you the perfect, complete package of magic, revenge, and romance. It's a masterclass in how to plot a satisfying fantasy romance trilogy across three volumes.
It's a trilogy. The definition of a trilogy is three works intended to be consumed in a specific sequence to tell one overarching story. 'Kingdom of the Wicked' fits that definition perfectly. Therefore, the order is implicitly defined by its nature as a trilogy.
While some series are more episodic, this is a continuous saga where each book directly continues the plot threads of the previous one.
My rule of thumb for any series: always read in publication order. Authors release stories in the order they want the information to be revealed. The 'Kingdom of the Wicked' series is no exception. The core emotional journey is Emilia's, and that's contained in the three novels. The novellas are delightful expansions, but they were conceived and released after the main arc was complete. Trust the publication timeline.
The reading order debates in this fandom are wild, honestly. I saw someone say you should read 'Throne of the Fallen' BETWEEN 'Kingdom of the Cursed' and 'Kingdom of the Feared' because of a timeline overlap. I tried that on a re-read and it was a mess. The pacing felt completely off, and the shift in protagonist focus was jarring.
Stick to publication order. The main trilogy is one continuous story. The spin-off is its own thing, with a new couple (Camilla and the sin lord of Envy) and a plot that runs parallel but doesn’t directly intersect with Emilia’s journey until maybe the very end. It’s better as a follow-up dessert, not a side dish.
The audiobook versions might influence order for some people. The novellas have their own narrations, and I think hearing them after the main books can be a lovely, intimate experience. It's like listening to a secret history. The vocal performances add another layer to the sisters' relationship. If you're an audiobook person, consider treating them as a bonus after the trilogy—a little extra content for your commute.