Normally players are allowed to go out by claiming a tile for a pair. This greatly increases players possibilities to complete their hands. Novice players often get in a situation where they are left with a single tile in their hand waiting for a missing tile from the Wall. If the missing tile can be claimed from another players discard, theres a good chance that a player still succeeds to complete his hand.
Note: This restriction is applied to regular hands only. For irregular hands any winning tile can be claimed (a tile that completes an irregular hand is not considered as a tile completing a set, even if it appears to complete a "Chow" or a "pair").
Claiming rules Chows
Claiming rules – Over-claiming
Claiming rules – Sacred Discard
Claiming rules – Missed Discard
Claiming rules Kuikae
Claiming rules – Competitive claims for going out