Fan (Points)
Scoring in Mahjongg is based on "fan" (doubles/points). The more special your hand, the more fan it's worth!
+1 fan: Pung of Dragons or your seat/round wind
+1 fan: Winning by self-draw (Tsumo)
+1 fan: Going out on the last tile of the wall
Many fan: Special hand patterns
Different regional variants have different scoring systems. The concepts are similar, but specific values vary!