Naki
Naki 「鳴き」, or "calls" in English, are legal claims on an immediately discarded tile. When an opponent discards a tile you can claim, you can call it to add it to your hand. After claiming a discard, the player's hand is considered open; an open hand cannot riichi, becomes unable to score some yaku, and have other yaku reduced in value. In addition, the tile group completed by a call is revealed and cannot be changed afterwards. However, calling allows the hand to complete faster.
Properties
For each immediate discard, players may claim a tile if:
- The hand contains two out of the three tiles necessary to form a complete tile group (see below).
- The claim was made immediately after the discard, before the next player's turn. Otherwise, a discarded tile remains in the discard pile.
- No player has made a call with a higher priority. Ron takes priority over all other calls. Pon/kan take priority over chii.
In addition, players may not call chii/pon/kan on the last discarded tile before the game ends in exhaustive draw.
Calls are not mandatory. When making a call for a discarded tile (chii, pon, open kan), your hand is considered open. As mentioned above, open hands cannot call riichi, are ineligible for certain yaku, and receive -1 han for certain other yaku.
Any call made by any player, except riichi and calls for a win, will immediately invalidate tenhou, chiihou, double riichi, ippatsu, and the option for kyuushu kyuuhai. This means that if the player to your left calls chii on the first turn, you cannot declare double riichi.
Procedure
When making a call, the tiles used for the call are revealed and placed to the side. These tiles are still considered part of the player's hand, but cannot be changed. Therefore, each call reduces the number of tiles you can choose to discard. After making a call, the player discards a tile.
The claimed tile must be arranged sideways to indicate the claimed tile. It must also be arranged on the left, middle, or right to indicate the source of the claim. This notation helps with the enforcement of furiten, as a claimed tile is still a part of the original player's discard pile.
Tile calls
Tile calls can only be formed when it would complete a mentsu or complete a winning hand. These are shown below:
| Chii | チー | Sequences |
| Pon | ポン | Three-of-a-kind |
| Kan | カン | Four-of-a-kind |
| Ron | ロン | Win on discard |
Chii
Chii 「チー」 completes a sequence, to form minjun.
Only the player to the right of the discarder may call chii. In other words, you can only call chii from the left player's discards. Therefore, the tile turned sideways is always indicated on the left. Chii may be particularly subject to the rule of kuikae - when calling a sequence, you cannot discard a tile that would have completed the same sequence. See below for details.
Pon
| Left | Across | Right |
  |
|
|
Pon 「ポン」 turns a pair of identical tiles into a minkou (open triplet).
Unlike chii, pon may be called from any player on the board. Because any player may call, sometimes a player's turn may be skipped.
Kan
Kan 「カン」 are triplets "upgraded" into four-of-a-kinds. Unlike the other calls, kan has some added procedures. In addition, there are three different types of kan:
- Daminkan (open kan) are called like pon, except you need to already have three of the same tile.
- Ankan (closed kan) can be called when four of the same tile are in your hand (without needing to claim a discarded tile). Ankan does not open your hand.
- Shouminkan (added kan) can be called when you have previously called pon, then draw the fourth tile yourself. This call turns the called triplet into a kan call.
You are not allowed to call a kan immediately after a pon/open kan/chii call.
All forms of kan are still considered triplets, just with one extra tile. Therefore, in order to maintain the hand, one tile is drawn from the dead wall. Also, any form of kan reveals kandora. For more information, see the kan page.
Agari
Agari 「アガリ」 is the generic call for a winning tile. However, it is rare, if ever, for anyone to actually call "Agari" upon winning. Instead, the term is used to describe the state of winning.
Ron
Ron 「ロン」 is a tile call to win from a discarded tile.
- You must have a winning shape and at least one yaku in order to win.
- You cannot ron under furiten.
Note that ron does not open the hand, however it does open the group of tiles. This means that, when competing a triplet via ron, the triplet is worth reduced fu, and the triplet no longer counts as a "closed triplet" in regards to fu or sanankou / suuankou. The hand itself is not opened, though, so yaku like iipeikou are unaffected (even if the winning tile completes the iipeikou, it still counts).
Call priority
When multiple players can call on a discard, the following takes priority (in order):
- Ron (Agari)
- Kan or Pon
- Chii
It is impossible for kan and pon to be called simultaneously; kan requires 3 copies of a tile in hand, pon requires 2 more copies of said tile, and there are only 4 copies of each tile. It is possible for pon/kan and chii to be called together; the player who calls pon gets the tile. A call for ron/agari will override any other tile call.
In real-life play
When playing with physical tiles, the following modifications to call priority may be used:[1]
- If both chii and pon (or kan) are called at the same time, or if the pon is called first, the pon will take priority as normal.
- If chii is called, then pon (or kan) is called noticeably after the chii, the chii happens and pon is invalidated. (You cannot obviously delay a pon to check if an opponent wants to chii.)
- A ron call, even if called late, still takes priority over all other calls.
Players who want to call pon should do so immediately, while players who want to call chii should wait a few moments to check if anyone wants to pon. To maintain the pace of the game, players should think about what tiles they want to call before they are discarded.
Kuikae
Kuikae is a rule which, when making a call, prevents you from immediately discarding a tile that could have completed that call. Under kuikae, calling pon on a 5-pin, then discarding a 5-pin is not allowed. Similarly, after calling chii on a 4-sou with 23-sou, you cannot discard a 1-sou or 4-sou. You are allowed to discard these tiles on any turn afterwards, just not on the turn you made the call. While it is not a fundamental rule, the kuikae restriction is common.
Kuisagari
Kuisagari 「喰い下がり」 is a property of some yaku to lose value when called open. When the hand is open, these yaku lose 1 han each:
| From 2 han to 1 han | From 3 han to 2 han | From 6 han to 5 han |
|---|---|---|
| Sanshoku | Honitsu | Chinitsu |
| Ittsu | Junchan | |
| Chanta |
Some yaku can only be scored in a closed hand - this is distinct from kuisagari. For example, ryanpeikou is impossible to score with an open hand; it does not drop from 3 -> 2 han. The other yaku can be scored open without penalty.
Atozuke
Atozuke is when a hand has no guaranteed yaku, but can gain yaku with a certain type of winning tile. This means that some of the "winning" tiles cannot be won off of due to a lack of yaku.
Example:
Waiting for: or
If the hand obtains the haku, it gains the yaku of yakuhai. If it obtains the 9-pin, it cannot win due to a lack of yaku.
Closed tile calls
| Kan | カン | Forming a quad |
| Kita | キタ | Picking a North dora |
| Riichi | リーチ | Ready hand declaration |
| Tsumo | ツモ | Win by self-draw |
These tile calls do not apply to discards, and therefore, do not open your hand. Just like the discard calls, these calls are announcements.
Kan
Apart from claiming a discard to form a quad, a quad may also be formed by adding the fourth tile from the hand to the open triplet, or by taking out four identical tiles form the hand.
Kita
In some rules of three-player mahjong, North tiles may be picked and functions as a dora.
Riichi
Riichi 「リーチ」 is a player's declaration for a ready hand. If desired, a player may announce riichi prior to discarding and invoke the rules involving riichi as a yaku. Riichi does not interrupt opponents' ippatsu, chiihou, etc.
Tsumo
Tsumo 「ツモ」 is the declaration for winning by self-draw. This may apply to any hand, open or closed. With a closed hand, it also counts as for the yaku, mentsumo. Even when furiten, it is acceptable to win the hand.
Open vs closed
Before making a tile call, players should consider "is it worth opening the hand, or is it better to remain closed?" Naturally, there are advantages to both. For starters, players should know the yaku and their hand values. A closed hand can call riichi and is thus worth more; an open hand is faster. Players should consider their point standing, hand value, number of tile draws left, and other factors before opening. For more details, see naki strategy.
Yakuman hands, assuming they can be won open, don't reduce in value after a call. Since they are so hard to complete, opening is often necessary to actually win with one.