As long as it’s timed right, humour can never be out of place! Humour is also really good for getting the reader to like/connect more to a character. At least for me, if a character is funny, I fall in love. It makes me want to keep turning the pages because I know a scene will never be dull with them around. When everything is all seriousness all the time, it gets kind of tiring. It’s one of the reasons why I end up not finishing a book/series.
I’ve been reading a series that’s thriller and not fantasy, but the plot is centred around really dark themes and serious threats to humanity. The author was so good at integrating humour into the appropriate moments, it made everything feel more real and the characters more rounded. I was chuckling to myself just as much as I was on the edge of my seat nervously biting my lip, and it never felt odd.