Rules Mastery
Every way a hand goes dead
The full list, so none of them surprise you.
Advanced · lesson 19 of 21
A hand can be declared dead for holding the wrong number of tiles, for an exposure that matches no hand on the card, for drawing out of turn or from the wrong place, for swapping a joker before picking, and for calling Mahjong on a hand that is not complete.
Note
Calling Mahjong wrongly is the costly one. Your hand is dead for the rest of the round, and you have just shown everyone exactly what you were holding.
The habit that prevents nearly all of it is counting your tiles before you discard, and reading the hand off the card once more before you declare.
Reading ahead is fine. The path takes lessons in order, so this one ticks off once you get here.
See where you are