If a great character doesn’t have a reasonable plot it won’t work and at the same time, if a fantastic plot has cardboard characters then neither will work, so it’s a tough question. However, if I had to choose, I’d say for me the character is absolutely the most important. Well developed, believable characters drive the plot, and sometimes even change the direction of a novel.
I always plan a novel through my main character or characters; for me it may be a woman who has a problem/ a sadness/ or something in her past that has brought her to this point and causes her to behave in a certain way. I like to know my character’s star signs, their favourite colours, foods and preferred music – all these elements help to build the character and help me to imagine their choices and the way they live. It may never be necessary to reveal all this minutiae to the reader – but it helps me as the writer to really get under my character’s skin, create realistic dialogue and decide how they would react to a situation or another person.by