Hanchan

Hanchan 「半荘」 encapsulates one game of Japanese mahjong. A typical game involves two rounds designated as East and then South. Even if a game ends early, such as when a player falls below zero points, then it is still considered to be a full game. For shorter games, players may play tonpussen 「東風戦」, or East only games.

Wind rounds

Hand #	Japanese	English
0	東局１本場０
1	東局２本場０
2	東局２本場１
3	東局３本場０
4	東局３本場１
5	東局４本場０
6	南局１本場０
7	南局１本場１
8	南局２本場０
9	南局２本場１
10	南局３本場０
11	南局３本場１
12	南局４本場０
13	西局１本場０
14	西局２本場０
15	西局２本場１
16	西局３本場０
17	西局４本場０
Source

Typical games begin with the East Round, or Tonkyoku 「東局」. After that, the game moves into the South Round, or Nankyoku 「南局」. If necessary, it can go into the West round, or shaakyoku 「西局」.

Hand designations

For identification and labeling, every hand has a designation. It uses a combination of the wind round, a number 1-4, and the honba count. As an example, the very first hand is always East Round 1, Honba 0. As the first hand of the game, it is impossible for it to have an alternative designation. All other hands afterwards may differ due to the different ways the game plays out.

Renchan

Renchan 「連荘」 are additional hands, by which the wind seating do not rotate. This is possible when the dealer wins a hand, an abortive draw occurs, or the dealer is tenpai at exhaustive draw.

In the event when the wind seating does not change, then the honba count increases by one. For each honba, the hand value for any player is increased by 300 points. To mark honba, the dealer uses a 100 point stick to mark the number of renchan currently. The points are used as markers only temporarily and is not spent by the dealer. When the dealer seating rotates, the dealer receives the markers back. A game cannot end with a renchan on board, unless a seat wind rotation occurs.

In the event of chombo, the wind seating may rotate if the dealer commits the penalty. Otherwise, it may not without an increase to the honba count.

Oorasu

Oorasu 「オーラス」 (All last) is designated for the last dealer of the game, barring any player ending the game earlier by dropping below zero points. This is the South 4 hand; for East only, it is the East 4 hand. Naturally, if the last dealer wins, an additional hand, or renchan, may be awarded and the game continues. Though, the game may also end if the last dealer happens to be the points leader, or if the other players force a wind rotation.

Agariyame

Agariyame 「和了り止め」 is a specialized rule applied at oorasu, where the last dealer makes the call to end the game after one hand, whether holding the lead or not. Otherwise, the same player may make the call to continue an additional hand, or renchan.

Enchousen

Enchousen 「延長戦」 is an extra round, provided that no player scored above the target points (typically 30,000) at the end of the game. This round functions like an "overtime sudden death period". The instant a player scores above the target points, then the game ends immediately; and the same player wins the game. For a regular hanchan game, this extra round is indicated as the West round. For tonpussen, the South round takes on this role.