Romantasy is a fusion of romance and fantasy in which both halves are essential: the love story and the worldbuilding develop together, and the romance sits at the centre of the plot rather than in a subplot. The genre boomed in 2023 and 2024 and became hugely popular on BookTok, helped by books like A Court of Thorns and Roses.
For new readers
If the book still works with the romance cut out, it is fantasy with romance; in romantasy the romance carries the plot.