The rules of Taiwanese mahjong, on one page

Most sources make 菊 3 and 竹 4; one app swaps them. Every flower in this app carries its number, so nobody has to remember.

Carries a bird; players call it 小鳥 or 么雞.

Each player draws one of the four wind tiles and sits accordingly, counterclockwise. Seats stay fixed for a 將 (four rounds).

East, South, West, North; four rounds make a 將. In the East round an East pung scores for anyone.

The player in the East chair rolls once to pick the first dealer; in that hand the dealer is also East. From then on the dice set East each hand.

Takes one more tile (17) and discards first. Keeps the deal after a win or a drawn hand; the deal passes only when a non-dealer wins.

The dealer lays out any flowers and draws the same number of replacements from the tail of the wall; then each player in turn. A flower drawn as a replacement waits for the next pass.

A drawn flower goes face up at once and you replace it from the tail; this can chain. Winning on the replacement scores 槓上開花 (1).

No replacement, no discard: the hand is drawn.

Only from 上家, the player whose discard comes just before your turn. The claimed tile goes in the middle.

From anyone. If you pass a pung on a tile, you may not pung the same tile again until your next turn.

A win beats a pung or kong, which beats a chow. Only one player wins off a discard: the first after the discarder in turn order (截胡). Taiwan does not play multiple winners.

After a pung, not the same tile. After a chow, not the claimed tile nor the tile at the other end of the run (chow a 3 with 4-5: neither 3 nor 6).

明槓: three in hand, the fourth from a discard. 暗槓: all four self-drawn, laid face down. 加槓: a self-drawn fourth added to a pung you already exposed. Every kong draws a replacement from the tail.

No exposed kong off 上家's discard. An added kong uses a self-drawn tile only. No kong right after a chow or pung. The replacement after an exposed kong cannot win by self-draw (after a concealed or added kong it can).

Only an added kong can be robbed. Robbing scores 1 and counts as that player's discard: they pay alone, and there is no 自摸.

花槓 is the 2-tai bonus for all four seasons or all four plants, not a kong.

One tile from a win. Declaring is optional; a declared ready hand is an app convention worth 1, and after declaring you may only discard the tile you draw.

If you could have won and did not, you may not win at all, self-draw included, until you discard a non-winning tile or make an added or concealed kong.

天聽 (8): ready on the dealt tiles, declared with the first discard. 地聽 (4): declared with the first discard after keeping the first draw. Both require that nobody has called. Sources define them in different ways.

Five sets and a pair, 17 tiles (more with kongs). A set is a chow (three in a row of one suit, no wrapping), a pung or a kong.

Self-draw (from the wall or a replacement), on a discard, by robbing a kong, or with flowers (八仙過海, 七搶一).

A zero-tai hand (屁胡) still wins, and takes the base.

Seven pairs, thirteen orphans, nine gates and 嚦咕嚦咕 are not part of Taiwanese 16-tile.

At 100/20, South self-draws a concealed hand with a pung of their seat wind: 4 tai. The dealer (East) is on 連1拉1. The dealer pays 100 + (4 + 3) × 20 = 240, the other two 180 each, and South collects 600.

See the dealer streak page, with a settle-up tool.

No payments.

The last 16 tiles are never drawn; each kong adds one more to the reserve.

The last drawable tile is 海底; self-drawing it is 海底撈月 (1). Whoever drew it still discards, and winning on that discard is 河底撈魚 (1).

With 3 or fewer tiles left, no chow, pung or exposed kong (concealed and added kongs are fine).

Nobody wins: no payment, and the dealer keeps the deal. There are no special draws for four winds or four kongs.

All eight flowers: an instant win worth 8, each of the three paying base + 8 tai (dealer tai apply). If the replacement also completes the hand, its tai add. Eight flowers in the dealt hand: 12.

You hold seven flowers and another player lays out the eighth: take it and win. The robbed player pays base + 8 tai alone. The same applies when your seventh arrives while another player already shows the eighth. The two Taipei tournaments do not play it; this app does by default.

Everything adds; big hands do not replace the rest, and there is no cap. "16-tai scale" means the biggest single pattern is 16, not that 16 is a ceiling.

A concealed self-draw is 3 in total (門清, 自摸, 不求), never 1 + 1.

大三元 and 小三元 replace 三元牌; 大四喜 replaces 圈風 and 門風 (小四喜 does not); 四暗刻 replaces 三暗刻; 天胡, 地胡 and 人胡 replace 門清, 自摸, 不求, 天聽 and 地聽.