Shogi, if you already play chess.

What carries over

• Two players, alternate moves, one piece per move, checkmate wins. Check must be answered. You may not leave your own king in check.
• The rook and the bishop move exactly as in chess. The king steps one square in any direction. Pawns go forward one square.
• Pieces are worth different amounts and trading well matters, though the values are different and, as you will see, trades do not simplify.

What is different

The board and the men

Nine by nine, all one colour, with 20 pieces a side. There is no queen. There are two generals, the gold and the silver, and a lance that runs straight forward. Pieces are flat wedges, all the same colour, and point at the enemy; you tell whose is whose by the direction they face.

The knight and the pawn are smaller

A shogi knight has two moves, not eight: two squares forward and one to the side, never sideways or back. A pawn moves and captures the same way, straight ahead; there is no double step, no en passant, and no diagonal capture. Pawns therefore face each other on a file and block each other until one is exchanged.

Drops

The one that matters. When you capture a piece it becomes yours, and on a later turn you may place it on almost any empty square as your move. Material never leaves the game; every exchange puts pieces into both hands. There is no endgame of the chess kind, no grinding a small advantage into a won pawn ending: with pieces raining back onto the board, the game is decided by the attack on the king. The drops page has the rules and the four restrictions.

Promotion is for almost everyone

In chess only the pawn promotes, and only on the last rank. In shogi six of the eight kinds promote, in any of the far three ranks, and each to one fixed piece: pawn, lance, knight and silver all become gold-movers; the rook and bishop keep their moves and add a king’s step. Promoted pieces are shown in red. See promotion.

No castling, but castles

There is no castling move. Instead the opening is spent walking the king into a corner and surrounding him with generals, a formation called a castle. Building one takes five to ten moves, and choosing one is the first strategic decision of the game. See castles.

Draws are rare

There is no stalemate draw: a player with no legal move has lost. Repeating a position four times is sennichite: professional games are replayed with colours reversed, and online services, this app included, score it a draw. If the repetition was forced by perpetual check, the checking side loses instead. The only other draw is the impasse, when both kings have run into the enemy camp and the pieces are counted. In practice, well over nine games in ten have a winner.

Notation

Files are counted 1 to 9 from the first player’s right, ranks a to i from the far side, and a move names the piece and where it went: P-7f. The Japanese write the same move ７六歩, and the app’s replay files use 7g7f. See reading moves.

What chess habits to keep, and to drop

Keep	Drop
Counting attackers and defenders on a square.	Simplifying when ahead. Exchanges arm the opponent too.
Developing before attacking.	Leaving the king in the centre. There is no safe centre in shogi.
Looking for forks and pins.	Treating pawns as small. A pawn in hand is the most useful piece you own.
Calculating checks first.	Expecting the knight to defend. It cannot move backward and is easily lost.