Objective: Recognize and avoid an illegal double Pawn on one file.
Quick answer: Nifu is the illegal position created when you drop a Pawn onto a file that already contains one of your unpromoted Pawns.
Best for: Players learning drops, especially chess players who are not used to pieces returning from capture.
In This Lesson
- Exactly which Pawns count for nifu.
- Why a Tokin does not block a Pawn drop under this rule.
- How to scan all nine files before dropping.
- How nifu differs from uchifuzume.
The Rule in One Sentence
You may not drop a Pawn on a file that already contains another unpromoted Pawn belonging to you. The Japanese term is commonly romanized as nifu, literally referring to two Pawns on one file.
Interactive Nifu Check
Sente already has an unpromoted Pawn on 5g and another Pawn in hand. Select the Pawn in hand. The fifth file is unavailable, while an otherwise legal empty square on another file remains available.
Correct Example
If Sente has a Pawn on 5g, dropping a Pawn on an empty square of the fourth file can be legal. The existing Pawn is on a different file, and the new Pawn must also satisfy the dead-rank and uchifuzume restrictions.
Illegal Example
With Sente’s unpromoted Pawn still on 5g, dropping another Sente Pawn anywhere on the fifth file is nifu. It does not matter how many ranks separate the two Pawns. The restriction follows the entire file.
What Counts and What Does Not?
| Piece already on the file | May you drop a Pawn? |
|---|---|
| Your unpromoted Pawn | No. That would be nifu. |
| Your promoted Pawn, a Tokin | Yes, if every other drop rule is satisfied. |
| Your opponent’s Pawn | Yes, if every other drop rule is satisfied. |
| No Pawn | Yes, subject to the last-rank and uchifuzume rules. |
A Reliable Board Scan
- Choose the destination square.
- Trace that file from rank a to rank i.
- Look only for your unpromoted Pawn.
- If one exists, choose another file or another move.
- If none exists, still check the last-rank and pawn-drop mate restrictions.
Typical Misunderstandings
- Nifu is checked by file, not by rank.
- An opponent’s Pawn does not create nifu for you.
- A Tokin moves like a Gold and no longer counts as an unpromoted Pawn for this restriction.
- Nifu applies to a Pawn drop. A legal board move can result in two Pawns of the same side appearing on one file only in unusual situations involving a promoted Pawn; two unpromoted Pawns cannot be produced by a legal drop.
Quick Check
Your unpromoted Pawn is on 5g. Which proposed drop avoids nifu?
A Pawn drop on the fourth file does not duplicate the existing unpromoted Pawn on the fifth file. The other choices remain on the fifth file.
Nifu and Game Results
Nifu is an illegal move, not a strategic penalty. Tournament procedures determine how an illegal move is recorded and penalized, so event regulations should be checked when playing competitively. On the 51Shogi legal board, prohibited Pawn-drop destinations are not offered as legal choices.
What Nifu Changes Strategically
A Pawn already advanced on a file can prevent a reinforcing Pawn drop on that same file. Before committing an edge or central Pawn, remember that its presence changes where a future Pawn in hand can be used. Promotion can also change the calculation: once that Pawn becomes a Tokin, it no longer counts as an unpromoted Pawn for nifu, although every other drop restriction still applies.
Review the broader shogi rules, check unfamiliar terms in the glossary, and use the Practice Board to compare files before a drop.
References and Review
Rule details were checked against the Japan Shogi Association regulations in English and the FESA rules. Content reviewed July 24, 2026.