Programming things is sometimes deceptively tricky. For UI things, the trickiness seems proportional to the number of possible interactions. The deception happens when a UI element is visually small relative to the number of possible interactions. It violates our intuition because the interaction density is abnormally high.

I feel like this could be generalized into a rule about the complexity and size of the input range(s) and the resulting trickiness, i.e. bug potential.

I usually caution folks on things that have what I call "high interaction density," but I sense that it doesn't land as well as it could.