A complete hand consists of four sets of Chows, Pungs and/or Kongs, and a pair. The winning tile can be received either from the Wall, as a supplement tile, or by claiming it from another player's discard at declaring out at the same time. For exceptions to the regular tile combinations, see Limit and Special Hands.
If you can complete your hand by claiming another players discard, you must declare Out by clicking the Out button of the Tile Claimed dialog box. (If you click Chow or Pung, instead, you may receive the tile and meld the set but you are not allowed to go out, but rather forced to discard one of the tiles in your hand).
If you receive the winning tile from the Wall, you can declare Out while it is your turn.
After the declaration the hand ends. If your declaration is valid, all tiles are turned face up and the Scores dialog box appears. Otherwise a message box informing about illegal declaration (and appropriate penalties) appears. If penalties for faulty declaration of Out are enabled, the Scores dialog box appears. Then a new deal is started (unless the game didnt end).
Note: Four Winds 1.x allowed human player to go out on a discard, even if he did not choose Out in the Tile Claimed dialog box. (E.g., the player could click Pung in the Tile Claimed dialog box, make his meld and then click the Out button on the status bar). This is no longer supported. (However, if you claim a tile for a Kong and get a supplement tile which lets you complete your hand, you are allowed to go out.)
Related procedures:
Declaring a Kong
Declaring Ready