COMPASS

A compass is the one item in this whole family that trades in both directions. A Librarian at expert sells one for 4 emeralds, and a Cartographer at journeyman will buy it straight back off you for 1 emerald, a round trip no other item on this site offers.

It is also the one item that hides inside other trades rather than only standing on its own. A Cartographer asks for a compass as a second cost, on top of the emeralds, on 6 separate map offers spread across his ladder. Skip past those pages without a compass in your inventory and the trade simply will not complete, no matter how many emeralds you are holding.

None of that changes what the item itself does: point at your set spawn, or spin uselessly in the Nether and the End where there is no fixed direction to find.

The Librarian is the only seller, and only once he has climbed to expert. The price sits flat at 4 emeralds for 1 compass, fixed in the trade file rather than rolled inside a range, so a second Librarian at the same tier never charges more or less.

Going the other way, a Cartographer at journeyman buys it off you for 1 emerald, which is worse than the crafting cost and mostly useful for clearing his early trade experience rather than as an income source.

The compass shows up again as an unlisted second cost on 6 Cartographer offers: village explorer map, swamp explorer map, jungle explorer map, ocean explorer map, trial chambers map, and woodland explorer map. None of those price tags mention the compass up front, so it is easy to walk up short one and have the trade refuse to complete.

The best rate any villager offers is an emerald for a single compass, from the Cartographer, and nothing else on the list pays out faster.

The Librarian at its expert tier asks 4 emeralds for a compass. 8 of the 72 villagers that pay emeralds, emptied out:

4 acacia boats against 104 flint for the same 4 emeralds, 26 times the carrying, and the shortest wait is the Leatherworker at 2.5 real minutes of shelf, gathering not counted. Compass itself pays 1 an emerald, so nothing in that table asks less and 62 ask more.

A lectern claims any unemployed villager as a Librarian right away, but the compass sale sits partway up his ladder rather than at the start. He opens at novice and only reaches expert, unlocked at 150 trade experience, after enough completed trades along the way.

Every sale before that point pays toward the same total, and this offer itself pays 15 experience once it opens, so 7 more purchases from it alone would already cover the next threshold.

Once open, the slot sells 12 compasses before locking, and a villager restocks at most twice a Minecraft day, so 24 is the most one Librarian will ever produce between sunrises.

12 compasses close the slot out, and the Librarian needs 2 real minutes back at his lectern before it opens again. A Minecraft day runs 20 real minutes, long enough for exactly two of those refills to land.

Stretched across a full day that puts one Librarian at 24 compasses for 96 emeralds total, the ceiling for a single villager no matter how much longer you stand there waiting.

Check the map offers first if that is what you actually need the compass for. Buying one from the Librarian only to hand it straight to a Cartographer as a second cost works, but it also means paying two villagers instead of shopping around for whichever one is cheaper that day.

Also on the Librarian's list: paper, bookshelf, enchanted book, book, red candle, and yellow candle.

The same Librarian pays an emerald per two book and quills you bring him, an easy way to fund a compass purchase without touching your own emerald stash.

Out of the crafting grid a compass points at the world spawn point, not at your bed and not at where you died. Sleeping moves where you respawn, but it does not move the needle, which is the single most common surprise for anyone using one to find their way home.

A lodestone changes that. Use a compass on one and the needle locks to that block instead, for as long as the lodestone stays where it is, which turns the item into a pointer to any place you choose. In the Nether and the End an ordinary compass spins uselessly, while a lodestone compass keeps working.

Hold a compass at a lodestone and it binds to that block instead of to spawn, permanently, and the item takes on a faint shimmer to show it. That is the only way to make a compass point at somewhere you chose, and a bound compass in an item frame is how a base marks its own front door.

Break the lodestone and the needle gives up entirely: it spins at random rather than falling back to spawn. The same spinning happens in the nether and the end, where a plain compass has no reference to point at.

A compass is also half of a map. Eight paper around one makes the map that shows where you are standing rather than only the ground you have walked.