Friction proportionality is the governing rule of traversability. It rests on a distinction between two kinds of difficulty. Necessary friction exists because a consequence genuinely requires competence, review, consent, or safety — accessing dangerous tools, removing a child from a parent’s custody, performing surgery. Accidental friction exists only because systems are poorly designed, agencies overlap, incentives conflict, no one owns the whole path, legacy procedures have piled up, or institutions quietly benefit from the difficulty. The first is protection; the second is drag.
The difficulty of traversing a pathway should be proportionate to the consequence of the action, not to the institutional complexity behind it.
Low-consequence actions should be easy; high-consequence actions should involve more review; and accidental friction should be removed aggressively. This is the same shape as the emergence rule that reversible beginnings should be easy while irreversible consequences are made harder — the two functions drawing one line from opposite sides. It also reframes ordinary administrative burden as a real ecological cost: attention consumed navigating accidental friction is wasted human capacity. See The Structural Principles.