Definition
The joker exchange lets a player, on their own turn, swap the natural tile a joker represents for that joker in any exposed set on the table.
The joker then goes into the exchanging player's hand. Only exposed jokers can be taken; hidden ones are safe.
Read the full guide: The Joker Exchange in American Mahjong: How Redeeming a Joker Works.
See it on real tiles: the coach reads any hand and names its direction, free, at the free read. Members get the coach on call for their own games.
More terms: Pung, Kong, Quint, Pair, Charleston, Blind pass, Courtesy pass, Joker.