A 108-tile wall with no honour tiles, the ding que rule that forces you to abandon one suit before play, and blood-battle scoring that continues until three players have won.
Winds and dragons are removed, so play runs quickly on the three number suits alone.
Before the hand begins you must abandon one suit, exactly as in Sichuan play.
A single win does not end the hand — play continues until three of the four players have won.
Before play starts you choose one of the three suits to abandon. You cannot win while tiles of that suit remain, so early decisions matter.
A hand does not end when someone wins. It continues until three of the four players have declared a winning hand.
No. Sichuan mahjong uses only pung and kong, which is part of why it plays so quickly.