World Riichi Championship Rules 2015 ～ Comments on the World Riichi Championship Rules 2015

5.5Winning on a discard (ron)

A player who can form a valid hand with at least one yaku with the last discarded tile can win by clearly declaring "ron", unless he is furiten.

5.6Winning on self-draw (tsumo)

A player who can form a valid hand with at least one yaku with a tile just drawn from the wall or the dead wall can win by clearly declaring "tsumo". The player should keep the winning tile apart from the rest of the hand, so it is clear to all players which was the winning tile. A player who is furiten can still win on self-draw.

If the player fails to keep the winning tile apart, his win is still valid but he will not score any minipoints or yaku requiring a particular wait. I.e. the pinfu yaku cannot be awarded in such a case.

5.6Winning on self-draw (tsumo)

If the player fails to keep the winning tile apart, his win is still valid but he will not score any minipoints or yaku requiring a particular wait.
As a side-effect, it makes it technically possible to score a 1 han 20 fu hand.

Dealer		Non-dealer
400 all	tsumo	200 / 400
1000	ron	700

Edit 2016-10-28:
The basic idea is you can't claim something you can't show.
• pinfu yaku: you need a 2-side wait
• minipoints for winning by self-draw: only for non-pinfu hands
• edge/closed/pair wait: (self explanatory)
Since you can't show any of those, you can't score them.
NB: In such a case, the hand is neither "pinfu" nor "not pinfu". So it invalidates both the pinfu yaku and self-draw's minipoints at the same time.

Of course, you still score stuff for which the wait doesn't matter, like Fully Concealed Hand, concealed pung, ...

5.7End of a hand

A hand can end in two ways: by exhaustive draw (no-one declares a win after the discard after the last tile) or by one player winning. Chonbo results in a re-deal and does not count as a hand.
There are no abortive draws.

5.7.1Last tile

The last tile can only be claimed for a win, not for a chow, pung or kong. In case a kong is declared at the second-to-last tile, the replacement tile becomes the last tile. It is not allowed to declare a concealed kong on the last tile.
The fourteen tiles of the dead wall are not used.

5.7.1Last tile

This is a standard rule to make sure there is one and only one last drawn tile, as well as one and only one last discarded tile.

5.7.2Exhaustive draw

An exhaustive draw occurs if no-one declares a win after the discard after the last tile.
After an exhaustive draw the players must announce if their hand is tenpai or noten. Tenpai hands must be shown (tiles turned face up). Noten hand must not be revealed. A player having a tenpai hand can choose to declare it noten and not reveal it, unless he had declared riichi.
Players announce if they are tenpai or noten in order: East player declares first, then South, then West, and finally North. It is permissible to declare out of turn, but the announcement cannot be changed.

Noten players pay a penalty to tenpai players.
The total noten penalty amounts to 3,000 points, shared between players as follow:

Number of noten players	Penalty paid by each noten player	Points earned by each tenpai players
0	–	0
1	3,000	1,000
2	1,500	1,500
3	1,000	3,000
4	0	–

Players who have declared riichi are obligated to show their tenpai hand in case of an exhaustive draw. If they can't, or won't, they will be penalized for noten riichi (see "wrong riichi declaration" in the fouls section).

After an exhaustive draw, a continuance counter is placed on the table at East’s right-hand side.

5.7.2Exhaustive draw

Noten riichi is penalized with a chonbo.

5.7.3No abortive draws

The World Riichi Championship Rules do not recognize any abortive draw cases.

5.7.3No abortive draws

To prepare the WRCR, I've run a survey of tournament riichi rules around the world. It shows that abortive draws are not that common.
Also, the four classic abortive cases don't make much sense when you think about it:
• Nine different terminals and honours: There are worst hands to start with.
• Four kongs: Nothing prevents the game to continue, the problem is only on the fifth kong. And even without aborting the hand, it prevents as well another player to get the Four Kongs yaku.
• Same wind discarded: Pure superstition.
• Four riichi: Indeed, it down-scales the game to a roulette and that's not fun, so this abortive case makes sense. But that's only about convenience, neglecting that different hands have different waits and thus different chances to win.

5.7.4Handling riichi bets after drawn games

In case of a drawn game, any riichi bets stay on the table to be claimed by the next player who declares a win.

Any riichi bets remaining on the table at the end of the hanchan stay on the table. Nobody collects them.

5.7.4Handling riichi bets after drawn games

You handle the handful of riichi bets by letting them where they are, which is pretty handy, but doesn't involve hands much.

5.7.5Furiten

A furiten or temporary furiten player is not allowed to claim a win on a discard. He can still win by self-draw.

• A player is furiten if he can form a valid hand with one of his previous discards, even if the hand would not have any yaku. A furiten player can choose to change his hand to avoid being furiten, unless he has declared riichi.

• A player is temporarily furiten if he fails to claim a win on a discard completing a valid hand, even if the hand would not have any yaku. This also applies for missing an opportunity to rob a kong.
The state of temporary furiten ends when the player draws or claims a tile, unless he has declared riichi. It does not matter if the set of turns is interrupted by claims for a chow, pung or kong: the player is still temporarily furiten until his next draw.
If the player had declared riichi, he remains temporarily furiten until the end of the hand.