The Joker Exchange, Step by Step

There are eight jokers in the game and there is no rule saying the ones on other people's racks are theirs to keep. If you have the tile a joker is standing in for, you can buy it out. They don't get a vote.

This is the single biggest jump in skill available to a new player, and most people play for months without using it.

How it works, in one sentence

On your turn, you hand over the natural tile that a joker is substituting for, and you take the joker.

That's it. The rest of this page is timing and edge cases.

When you're allowed

Step three. After you've picked from the wall — or claimed a discard and finished the exposure — and before you discard.

Not on someone else's turn. Not before you've picked. And never by claiming a discard for the purpose of exchanging: a discard may only be claimed to make an exposure or to win.

What you can raid

Any exposure on the table. Yours, the player next to you, the player across, somebody whose hand went dead twenty minutes ago. If a joker is sitting in an exposure and you hold the tile it represents, it's available.

The exchange isn't a negotiation — every published rulebook describes it as an action the redeemer takes, and none of them contemplates the other player saying no. But there's no reason to be smug about it, and you'll want the same courtesy in ten minutes.

What you get, and where it goes

The joker goes into the concealed part of your rack — behind the slope, with the rest of your hand. The one exception is if you're using it to declare mahjong immediately, in which case it goes straight into your winning hand.

What it costs you

So if you were planning to modify an exposure — do it first. Discarding has the same locking effect, which means in practice your exposures are only flexible during the short window between claiming a tile and taking your next action.

Things you cannot do

• Reverse it. You can't put a joker into an exposure to pull a natural tile out. The trade runs one way only.
• Use a claimed discard. You can't call a tile off the table specifically to fund an exchange.
• Modify an exposure with a joker you just got. It goes into your hand, not into an existing group.
• Do it on someone else's turn. However obvious the opportunity, wait.

Things you can do that surprise people

• Several in one turn. If you hold three tiles that match three jokers across the table, take all three.
• From your own exposure. Same rules — you give the natural tile.
• While playing a concealed hand. You have nothing exposed, but everyone else does, and their jokers are fair game.
• From a dead hand — usually. The exposure is still sitting there and its jokers normally stay live. The exception is an exposure that already gives the hand away as unwinnable, nonexistent or concealed. Sources disagree most here, so ask rather than assume.

Why it's worth doing even when you don't need the joker

Two reasons that have nothing to do with your own hand.

First, the payout. Winning by joker exchange counts as self-picked, which means everyone pays double instead of just the discarder. If the exchange completes your hand, it's worth materially more than winning on somebody's discard.

Second, denial. A joker in an opponent's exposure is a joker they might otherwise trade for later. Taking it costs them flexibility, and in a tight endgame that matters.

A worked example

The player across from you has an exposed pung of three bam: two natural three bams and a joker. You're holding a three bam you don't need.

On your turn, you pick from the wall. Nothing useful. Before discarding, you say "could I take your joker?", put your three bam down, and take the joker. Their exposure is now three natural three bams — still a legal pung, still theirs. You have a joker you didn't have thirty seconds ago. Then you discard and the turn passes.

Nothing about that was unusual, and most tables see it half a dozen times an evening.