Minishogi ”５五将棋” is identical to standard shogi with the following exceptions:
Game equipment
Two players play on a board ruled into a grid of 5 ranks (rows) by 5 files (columns). The squares are undifferentiated by marking or color.
Each player has a set of 6 wedge-shaped pieces. The pieces are of slightly different sizes. From largest to smallest (or most to least powerful) they are:
- 1 king ”王将”（Oushou)
- 1 rook ”飛車”（Hisha)
- 1 bishop ”角行”（Kakugyou)
- 1 gold general ”金将”（Kinshou)
- 1 silver general ”銀将”（Ginshou）
- 1 pawn ”歩兵”（Fufyou)
These are identical to the standard pieces of the same names.
Setup
The following figure is the initial position of Mini-Shogi.
The starting setup of a game of Mini-Shogi.
In the rank nearest the player:
- The king is placed in the left corner file.
- The gold general is placed in the adjacent file to the king.
- The silver general is placed adjacent to the gold general.
- The bishop is placed adjacent to the silver general.
- The rook is placed in the right corner, adjacent to the bishop.
- That is, the first rank is |K|G|S|B|R|.
- In the second rank, each player places the pawn in the same file as the king.
Promotion
These are as in standard shogi, except that the promotion zone is the farthest rank away from you.
Pieces promote as they do in shogi.
- Silver -> Promoted Silver "成銀”（Narigin)
- Bishop -> Promoted bishop (Horse) ”馬”(Uma)
- Rook -> Promoted rook (Dragon) ”竜”(Ryuu)
Drops
You can drop like you do in shogi as well.
There are two other restrictions when dropping pawns:
- A pawn cannot be dropped onto the same file (column) as another unpromoted pawn controlled by the same player. (A tokin does not count as a pawn.) A player who has an unpromoted pawn on every file is therefore unable to drop a pawn anywhere.
- A pawn cannot be dropped to give an immediate checkmate. However, other pieces may be dropped to give immediate checkmate, a pawn that is already on the board may be advanced to give checkmate, and a pawn may be dropped so that either it or another piece can give checkmate on a subsequent turn.
Sennichite: fourfold repitation
If the same game position occurs four times with the same player to move, either player loses if his or her moves during the repetition are all checks (perpetual check), otherwise "Sente"(Black) loses.
Cited References