The number four in Chinese characters.
Four (si) is considered unlucky as it sounds like death in Chinese. Many buildings skip the 4th floor.
Character Suit
Match with an identical tile. Both tiles must be free (no tile on top, at least one open side).
4 identical tiles per standard set
Despite its unlucky reputation, Character 4 is just another tile to match. Clear it early.
Explore all tiles in the Mahjong Tile Guide to learn matching strategies for every suit.