Maybe the most vivid and immediate appeal of fantasy fiction is that of visiting another world. The other enticements—exploring the human condition, reading about some neat swordfights—come later. Like a lot of SFF writers, I got my start writing a series of travel guides to imaginary kingdoms, with narrative and character turning up later.
But I’ve always really loved fantasy worlds where there isn’t just one imaginary place, either existing by itself or connected to our own working-day world, but a whole nexus of interconnected universes. In space opera, for instance, the idea of visiting other worlds is commonplace—but here I’m not talking about visiting many other planets but many other realities. Philip Pullman’s His Dark Materials books were my introduction to this kind of multiverse, but they surely need no introduction! In this kind of setting, every world has its own rules to learn and its own dangers to face. There is a sense of infinite possibility and variety, with just a hint at the cliff-edge terror of immensity, the ever-present risk that you might get lost far from home.