16 BIT
MAHJONG

So far a turn only uses tiles you draw yourself. Here is the rule that makes mahjong a game rather than four people playing solitaire:

A DISCARD IS BRIEFLY UP FOR GRABS

When a player discards, that tile is briefly available. If it completes a set for you AND that particular claim is legal from that seat, you can CLAIM it — take it out of the discard and use it immediately.

The seat matters, and lesson 7-4 is entirely about it: pung and kong are legal from any player, chow only from one. For now, the idea to hold onto is that discards are not dead tiles.

You do not have to wait for your turn. That is the point.

WHAT CLAIMING BUYS YOU

Speed. A tile you would have waited ten turns to draw is yours now.

Claiming is how a hand goes from hopeless to one-away in a single move.

WHAT CLAIMING COSTS YOU

The set becomes EXPOSED. You lay it face-up on the table and it stays there for the rest of the hand.

That costs you two things:

1. INFORMATION. Everyone can now see part of your hand. A player who sees you expose two bamboo sets will stop discarding bamboo.

2. VALUE. Many of the better scoring hands require a fully concealed hand. One claim can close those doors permanently.

So the real question is never 'can I claim this?' — it is 'is this tile worth showing my hand for?'

Early in a hand, with a hand that is far from finished, usually yes.

Late, holding a concealed hand worth real points, often no.

The next three lessons are the rules that decide WHICH claims are legal and WHO gets the tile when more than one player wants it.