On maps and atlases, a “trap street” is either a fake, misnamed, or misrepresented street — the passage may be curved and shown as straight or vice versa. The intention is to “trap” cartography copycats, enabling the original artist to pin them down with unanswerable questions about the duplicates origins in a court of law (or field of battle depending on the region and seriousness of the crime).
Like so many human endeavors, mortal truth unintentionally parallels the Netherworld.
From tiny villages to immense cities, communities of all sizes gain sentience over time. Their movements and actions are typically too slow or subtle for human perception, creating the illusion of a space to be controlled and changed. In reality, communities adjust their features and layouts over time, much in the same way you or I adjust
a garment to fit better.
Ghosts and non-corporeal undead will notice but rarely take into account the changes. The ability to pass through walls means having to pay little attention to shifting landscapes and architecture beyond a passing curiosity.
Monsters notice significantly more. With the innate ability to travel in plain sight without being perceived, they are masters of adaption. Most monsters are so in tune with their home that following, even aiding, the shifting of streets is as natural as breathing.
For witches and other magic users, the street changes can be a source of communication. After living with an area for a while, they can read and be warned of danger simply by wandering about and taking stock in movements of pathways and light sources.
Travelers and adventurers must beware, for while all of this may seem enjoyable and light hearted, it should be noted that some cities actively use trap streets to corner and destroy those that displease them. In these instances, they are quite literally trap streets.