Gunjin Shogi (Military Chess)

Overview

Gunjin Shogi is a 2-player strategy board game where players deploy military-themed pieces face-down on the board, then take turns moving and attacking. A computer referee resolves combat based on piece ranks. The game features hidden information — you cannot see your opponent's pieces.

Board

The board is 8 columns × 9 rows:

• Rows 0–3: Player 1 territory
• Row 4: Passage zone (2 passages at columns 1 and 6, connected to entry points on each side)
• Rows 5–8: Player 2 territory
• Each player has a 総司令部 (Headquarters) spanning columns 3–4 in their back row

Setup

Both players simultaneously place 31 pieces face-down in their 4×8 territory (the 総司令部 cell cannot hold a piece). Once both players confirm placement, the game begins.

• Landmines cannot be placed on the 総司令部 or passage entrances
• Flag cannot be placed on passage entrances

Pieces (31 per player)

Piece	Count	Rank	Special
General (大将)	1	10	Highest rank
Lt. General (中将)	1	9
Maj. General (少将)	2	8
Colonel (大佐)	2	7
Lt. Colonel (中佐)	2	6
Major (少佐)	2	5
Captain (大尉)	2	4
Lieutenant (中尉)	2	3
Sub-Lt. (少尉)	2	2
Cavalry (騎兵)	2	1	Can move 2 squares forward
Engineer (工兵)	3	—	Moves like a rook; defeats landmines
Spy (スパイ)	1	—	Defeats the General; loses to all others
Tank (タンク)	3	—	Beats rank ≤ 7; can move 2 forward
Airplane (ヒコーキ)	2	—	Unlimited vertical; flies over everything
Landmine (地雷)	3	—	Immobile; destroys attackers (both removed)
Flag (軍旗)	1	—	Immobile; takes strength of piece behind it

Movement

• Most pieces move 1 square orthogonally (up/down/left/right)
• Cavalry / Tank: Can also move 2 squares forward (if path is clear)
• Engineer: Moves any number of squares in a straight line (like a rook in chess), blocked by other pieces
• Airplane: Unlimited vertical movement (flies over all obstacles); 1 square horizontal
• Landmine / Flag: Cannot move
• Only officers (Major or higher, ranks 5–10) can enter the opponent's 総司令部

Passage Zone

The middle zone can only be crossed through 2 passages (entry point → passage → opponent's entry point). Airplane ignores this restriction and can invade enemy territory from any column.

Special movement through passages:

• Cavalry / Tank: Can pass through a passage in one move (entry point → passage → opponent's entry point, counting as 2 steps forward), but only in a straight line (same column). If the column changes, the piece must stop at the passage. They can also enter a passage from 1 square behind the entry point (counting as 2 steps: 1 forward to entry point + passage). Cannot pass through if a piece occupies the passage
• Engineer: Can pass through a passage and continue moving in a straight line forward from the opponent's entry point (same column only; cross-column requires stopping at the passage). If an Engineer reaches an entry point via forward rook-like movement (same column), it can continue into the passage and through to the other side in the same move. Cannot pass through if a piece occupies the passage. An Engineer on a passage can exit to any connected entry point and continue its rook-like movement

Combat

When a piece moves onto an opponent's piece, combat is resolved automatically:

• Higher rank wins (lower rank piece is removed)
• Same rank: Both pieces are removed
• Spy vs General: Spy wins
• Spy vs anything else: Spy loses
• Landmine: Destroys any attacker (both removed). Exception: Engineer and Airplane defeat landmines cleanly
• Tank: Beats Colonel (rank 7) and below. Loses to Generals (rank 8+) and Airplane
• Airplane: Beats Colonel (rank 7) and below. Loses to Generals (rank 8+)
• Flag: Takes the combat strength of the piece directly behind it (toward own back row). If no piece is behind it, it is defenseless

Pieces involved in combat remain hidden — only the outcome (which piece survives) is visible, not the piece types.

Victory Conditions

1. Occupy the opponent's 総司令部 with an officer (Major or higher, ranks 5–10) → Immediate win
2. Eliminate all of the opponent's officers → Win (opponent can no longer occupy your 総司令部)