Bao 包Pay allDangerous discards
Singapore Mahjong Bao rules
Bao 包 is the table warning that one player's discard has created liability. If the threatened hand wins under the matching conditions, that one player covers the table's payment.
Before every late discard
Scan exposed tiles, then scan the discard pool
You do not need to calculate every hidden possibility. Bao risk comes from visible information: exposed sets, exposed Fan, suit concentration, and whether a late tile is fresh.
Honor scan
Two Dragon sets or three Wind sets make the missing Honor dangerous.
Value scan
Near the cap, a Dragon or valuable Wind can trigger liability.
Suit and wall scan
Three same-suit sets or fewer than four playable tiles should slow your discard.
Bao case 1
Feeding the third Dragon
An opponent already shows Pongs or Kongs of two Dragons. You discard the missing Dragon and they use it for a Pong, Kong, or Win that completes the full Dragon set.
Trigger
Your discard completes the opponent's third Dragon set by Pong, Kong, or Win.
Continuing liability
The original discarder can remain liable if that opponent later self-draws the win or receives the winning discard from that same liable player.
Bao case 2
Feeding the fourth Wind
An opponent already shows Pongs or Kongs of three Winds. You discard the missing Wind and they use it for a Pong, Kong, or Win that completes all four Wind sets.
The same continuing-liability rule applies: a later self-draw or a later winning discard from the original liable player can still leave that player paying all.
Bao case 3
Feeding visible Fan at the limit
Count only the Fan already visible in exposed tiles. The default payout cap here is 5 Fan.
| Visible value | Dangerous discard | What must happen |
|---|---|---|
| 5 exposed Fan | Dragon, Prevailing Wind, or Seat Wind | The tile is used for Win, Pong, or Kong. |
| 4 exposed Fan | Dragon, Prevailing Wind, or Seat Wind | The tile forms a Pong or Kong—including a winning Pong—and reaches 5 Fan. |
| 3 exposed Fan | The one Wind that is both Prevailing and Seat Wind | Its set is worth 2 Fan and reaches the 5-Fan limit. |
Like the Dragon and Wind-set cases, liability can continue to a later self-drawn win or a later winning discard from the original liable player.
Bao case 4
Completing an exposed Full Color hand
An opponent shows three or four Chows, Pongs, or Kongs from one numbered suit. You discard a tile from that suit and it directly completes their Full Color win.
Bao case 5
Throwing a fresh winning tile at the end
Fewer than four playable tiles remain. You discard a tile that has not appeared in the discard pool, and another player wins with it.
“Fresh” means absent from the visible discard pool—not merely a tile you have not personally discarded. Tables may agree on a different late-game window before play.
Five-second checklist
Before discarding, ask these five questions
- Are two Dragon sets already exposed?
- Are three Wind sets already exposed?
- Does the opponent show 4 or 5 Fan—or 3 Fan with a double-value Wind?
- Are three or four exposed sets all from one numbered suit?
- Are fewer than four playable tiles left, and is my discard fresh?
Fast answers
Bao FAQ
Does every dangerous-looking discard create Bao?
No. Each case has a specific exposed state and a specific use of the discarded tile. Read the matching condition before assigning liability.
Can a late fresh tile that makes a Kong be Bao?
That is a common optional variation, often used with fewer than seven playable tiles, but it is not part of this guide's default five cases.
Does Bao change the winner's Fan?
No. Score the winning hand normally. Bao changes who is responsible for paying the table amount.
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