I am looking for an English word that would describe, for a concept, the property of being tricky to reason about. Something that does not fit naturally in the mind and causes us to reason incorrectly.
The closest I have come up with is "inscrutability" or perhaps "abstrusity". However, both convey the idea that the concept feels immediately opaque upon inspection. I would like a work that also works for describing concepts that may seem easy to reason about, but which end up being tricky.
Edit: some good suggestions already. I'm looking for something that doesn't necessarily have to be tricky, counterintuitive, or deceptive, but that could. The problem is that abstrusity seems to exclude concepts which may seem superficially simple. Complexity gets close, but it conflicts with another use of the work in the domain I am writing about (programming language theory).
Edit2: equivocality is a possibility, but too much emphasis is placed on ambiguity and it seems to exclude obscurity which can also be a source of confusion.