I would describe the world as a prevalent low magic steam punk desert world. Magic is everywhere but none too strong, it is a fact of life and little magical trinkets can be found in almost every home. One large difference is the almost complete absence of traditional divine magic
Drow had disappeared for a century and the underdark had become an even more terrifying and dangerous place with their absence. They started to show up again, unfortunate dimensional travelers, exiles and the like. None have any idea what happened to the original members of their race that inhabited this material plane and every short handed attempt to reclaim their forbearers underdark home has met with bloody failure.
Teleport, dimension hop, and other such spells carry with them a % chance to go terribly terribly wrong. as the distance traversed by the spell is increased the chance of misfortune becomes greater and greater effectively rendering long distance travel via spells suicide.
aside from the shadow and ethereal plains travel off the prime material is impossible. but dragging things into the the plains is perfectly doable. this makes summoning intelligent beings a slippery slope, as if summoned in from outside of the plain they may become irate once they realize where they are.