Before play, for every riddle worth being stuck on, write three seals and close them: the Nudge (a single word or image), the Bearing (what to do, never why), and the Answer (plain as porridge).
Put them on the table. Sealed, visible, in order. Players should see that help exists and costs something; that is half the mechanism working already.
Every road opens the next seal. The captain's menu, a letter to an absent friend, honest searching in the fiction — all draw from the same three seals, in order. A road decides the price and the postage, never the contents.
No road skips ahead — save the Captain's Chart, which opens every remaining seal at once. That is why they shouldn't order it.
Cleverness is banked. Solve the riddle while seals remain closed, and each unopened seal becomes a grace: one free, graceful asking, held for later. Doing it yourself pays forward.
Mercy clause. If all three seals are open and the table is still aground, the Answer is simply true and the story moves. Nothing in these papers is allowed to sink the ship.
The seals are not a cage for the story. They are a promise that no one drowns in a riddle.