What is this?

This is a network version of Minefield Mahjong, a game described in the manga Kaiji by Nobuyuki Fukumoto.

How do I play?

Minefield Mahjong is a two-player game in which the players try to get each other to deal into their hand.

Assuming you already know the rules of Riichi Mahjong (if not, you should look at some other sources, like Wikipedia or The Mahjong Guide):

• The players shuffle the tiles and arrange them into four walls, as usual.
• In the first phase, each player receives the 34 tiles from the wall closest to them.
  • Within the next 3 minutes, they have to create a waiting hand (13 tiles) worth at least a mangan.
  • The score always includes riichi as well as dora (determined at the beginning by flipping one of the tiles from the remaining walls).
• In the second phase, the players deal remaining tiles one by one, 17 times.
• You win if the other player deals into your hand.

How are the hands scored?

There is a number of subtleties in scoring Minefield hands:

• We use mangan rounding-up. This means that 4 fan 30 fu hand (for instance, riichi dora tanyao pinfu) as well as 3 fan 60 fu hand are mangan.
• Riichi is always included. There is also ippatsu (win on the first dealing) and houtei (win on the last one).
• Apart from dora, there is also uradora, revealed after the win. However, your hand has to be a mangan even without uradora.
• Watch out for furiten! Unfortunately, it applies even if either you or your opponent deals one of your cheaper (that is, non-mangan) waits.
• There's no round wind, only your seat wind.
• There is no kan.

Is my browser supported?

Minefield supports recent versions of Chrome and Firefox. This is a hobby project and we like to play with all the shiny new features :)

However, if this is a problem for you, don't hesitate to contact us - we might be able to help.

What technology do you use?

For the user interface, we use React and Redux.

The server is written in Rust. We use WebSockets for communication.

How do I contact you?

We welcome all kinds of questions, wishes, suggestions, bug reports, corrections to this FAQ and other feedback!

Simply write an e-mail to pwmarcz at gmail dot com.

日本語でメッセージも大歓迎！

日本語翻訳で手伝う人を探しています。