What is Dahai?
Dahai is the action of selecting and discarding one tile from your hand. After drawing (tsumo), you must discard to return your hand from 14 tiles to 13. This fundamental action, repeated throughout the game, is central to mahjong strategy.
Which tile you choose to discard determines both your hand development and defense, making dahai a core skill.
Basic Rules
| Element | Description |
|---|---|
| Timing | After drawing or initial deal |
| Quantity | Always exactly 1 tile |
| Hand state | 14 tiles → 13 tiles |
| Time limit | Usually several seconds |
| Reversal | Not allowed once released |
Types of Discards
| Type | Description | Characteristic |
|---|---|---|
| Tsumogiri | Discard the drawn tile | Doesn’t change hand |
| Tedashi | Discard from hand | Progresses hand |
| Karakiri | Swap same tile | Hides information |
| Safe discard | Choose safe tile | Defensive |
Discard Flow
Standard sequence:
1. Hand becomes 14 tiles (draw/deal)
2. Select unwanted tile
3. Place in river (discard area)
4. Hand returns to 13 tiles
5. Next player's turn
*Continues unless calledProper Etiquette
Correct Method
Recommended discard technique:
1. Select your tile
2. Check proper position in river
3. Place gently
4. Arrange in rows of 6
5. Position visibly for allProhibited Actions
| Bad Practice | Reason | Correct Method |
|---|---|---|
| Slamming | Intimidating, damages tiles | Place quietly |
| Throwing | Poor manners | Place carefully |
| Hidden placement | Appears suspicious | Visible to all |
| Messy arrangement | Hard to verify | Arrange neatly |
Strategic Discards
Early Game
Basic early game approach:
1. Discard honor tiles first (safe)
2. Prioritize terminal tiles
3. Remove isolated tiles
4. Consider hand shape
5. Keep dora tilesMid Game
| Situation | Discard Policy | Reason |
|---|---|---|
| Near good tenpai | Aggressive | Aim for win |
| Opponent riichi | Safe tiles first | Avoid deal-in |
| Hand is slow | Balanced | Wait and see |
| Going for value | Selective | Prioritize yaku |
Late Game
Late game considerations:
- Are you in tenpai?
- Point situation
- Remaining turns
- Opponents' status
- Available safe tilesReading Discards
Information from Discard Order
| Pattern | Likely Situation |
|---|---|
| Honors→terminals→simples | Normal progression |
| Same suit heavy | Flush hand likely |
| Many middle tiles | Tanyao attempt |
| Terminals remain | Yakuman warning |
Tsumogiri vs Tedashi
Distinguishing them:
1. Speed of action
- Tsumogiri: Fast
- Tedashi: Slower
2. Hand movement
- Tsumogiri: From right side
- Tedashi: From within hand
3. Thinking time
- Tsumogiri: Short
- Tedashi: LongerTile Efficiency Priority
| Priority | Tile Type | Reason |
|---|---|---|
| 1st | Guest winds | Non-valuable honors |
| 2nd | Isolated terminals | Hard to use |
| 3rd | Bad shape tiles | Poor waits |
| 4th | Extra pair tile | Surplus |
| Last | Dora, yakuhai | High value |
Common Mistakes
-
Rushing discards
- You have time to think
- Don’t panic
-
Trying to take back
- Once released, it’s final
- Be careful in selection
-
Wrong count
- Always discard exactly 1
- Don’t forget to discard
-
Etiquette violations
- Don’t slam tiles
- Keep river organized
Online vs Real Mahjong
| Element | Real Mahjong | Online |
|---|---|---|
| Time limit | Flexible | Strict |
| Reversal | Negotiable | System blocks |
| Appearance | Personal style | Uniform |
| Sound | Natural | Sound effects |
Related Terms
- Tsumo: Drawing a tile
- Kawa: Discard area (river)
- Sutehai: Discarded tiles
- Tehai: Hand tiles
- Tsumogiri: Discarding drawn tile
Summary
Dahai (discarding) is the fundamental action of selecting and placing a tile in your river. While it seems simple, which tile you choose determines wins and losses. Beginners should first learn proper etiquette - discard gently, arrange tiles visibly in rows of 6. As you improve, consider tile efficiency and opponents’ movements for strategic discards.