Suzumu Shogi

Suzumu Shogi (進将棋 suzumu shōgi, literally "advance shogi," but meant in the sense of "hexadecimal shogi") is a large Shogi variant based on Tenjiku Shogi, which is among the most fast-paced chess variants out there, despite its huge size (16x16 board with 78 pieces per player). In fact it is so fast paced that it can easily devolve into a one-man show where a Fire Demon easily burns away everything in its path or a jumping General delivers a smothered mate (in rulesets where jump-capture of royalty is allowed). Chess is meant to be a team game, and chess variants of all kinds are no exception. So I decided to make Suzumu Shogi a version of the Tenjiku Shogi with the strongest pieces severely weakened (but with more options for how to utilize their moves as a compensation), and the weakest pieces boosted. This makes it actually feel like a team game, as the strongest pieces now need each other's help to break through the opposing army's defenses. I also took the opportunity to eliminate the remaining lacunae in the game's rules to eliminate any possibility of confusion.

Most pieces move like their counterparts in Tenjiku Shogi, assuming you are using the Wikipedia/CVP ruleset. However, there are exceptions. The Fire Demon can optionally burn up to two non-Fire Demon pieces of its choosing adjacent to another square. Furthermore, instead of passivly burning pieces on the opponent's turn, it can capture up to two adjacent pieces without moving, which is known as double igui and has no restrictions. The jumping Generals can only jump two pieces at most, but can optionally capture any enemy pieces they jump over, and have no restrictions on what they can capture. The Heavenly Tetrarch has the double igui ability and can freeze (immobilize) adjacent non-Heavenly Tetrarch pieces, and the Lance, Knight, and Iron General are boosted in ways that let them move backwards, and in the case of the latter two reach every square on the board.

Setup

Suzumu Shogi uses the same pieces and initial position as Tenjiku Shogi. An interactive diagram has been provided (The Javascript source code was written by H. G. Muller) to make it easier to understand how each piece moves. The Mnemonic piece directory uses H. G. Muller's Mnemonic pieces. The white Shogi pieces used in the diagram and the Pieces section are my own pieces, made using a free online pixel art drawing tool called Pixilart.

Only the location of the pieces of one side are mentioned below. The setup for the other side can be obtained by rotating the board 180 degrees. The promotion and XBetza notation of each piece has been included in brackets for easier reference ([ixK] is an ad hoc atom for immobilizing adjacent pieces, and [R] indicates that the piece has restrictions on its movement or abilities).

Lines below can be clicked to see how the pieces move:

Pieces

The move of pieces from the initial setup is already given in Betza notation above, and should also be clear from the mnemonic piece glyphs in the diagram. Some pieces that move in special ways are discussed below.

Fire Demon

The Fire Demon can slide sideways or diagonally, or make an 'area move' - up to 3 King steps in independently chosen directions, stopping at the first capture, including returning to the starting square to skip a turn. In addition, it has the power to "burn"; it can move to another square and then capture up to two non-Fire Demon opponents adjacent to that square without moving. Or it can simply capture up to two adjacent opponents without moving (double igui).

The Fire Demon cannot burn another Fire Demon (move to another square and then capture a Fire Demon without moving). It can capture a Fire Demon via any other type of capture however, and can even capture other pieces after the fact, as long as this does not involve burning a Fire Demon.

Heavenly Tetrarch

The Heavenly Tetrarch is a sliding piece that skips the first square in any direction, totally ignoring (and not affecting) what is on it. It can end maximally 3 squares away from its starting square sideways, but can slide arbitrarily far in all other directions. Like any slider it must stop after a capture, or before hitting a friendly piece. Alternatively the Heavenly Tetrarch can annihilate up to two opponents next to it, without moving (double igui). In addition, it has the power to "freeze"; all stationary non-Heavenly Tetrarch opponents are immobilized, and cannot move at all (not even to skip a turn) until the Heavenly Tetrarch moves away or is captured.

Heavenly Tetrarches cannot freeze each other.

Jumping Sliders

The Bishop General, Rook General, Vice General, and Great General move as Bishop, Rook, Bishop, and Queen respectively. But when capturing, all these Generals can jump over up to two other pieces, and each enemy piece they jump over may be either captured or ignored. However, they can only jump pieces of lower rank, whether friend or foe. The ranking is, in descending order:

1. King and Prince
2. Great General
3. Vice General
4. Rook General and Bishop General
5. All other pieces

These pieces can capture each other irrespective of rank, even when jumping something else.

The Vice General can also make an 'area move' - up to 3 King steps in independently chosen directions, stopping at the first capture, including returning to the starting square to skip a turn.

Lion and Lion Hawk

The Lion and Lion Hawk are double movers: they can make up to 2 King steps per turn, changing direction between them, even when this returns them to their starting square. They can make the first step as a jump, when they choose to do so. So each of them can:

• Jump directly to any square in the 5x5 area surrounding it,
• Annihilate any opponent standing next to it, without moving (formally one step, and then a step back),
• Annihilate any opponent standing next to it, moving on to an empty square next to that ('hit and run'),
• Annihilate any opponent standing next to it, and normally capture an opponent standing next to that ('double capture'),
• Stay in place without capturing anything if one of the neighboring squares is empty (effectively passing a turn)

The Lion Hawk can in addition move as a normal Bishop.

In other words, the Lion Hawk is a Lion enhanced by the diagonal moves of a Queen.

Free Eagle

The Free Eagle can move as a Queen, but as an alternative can make two diagonal steps, in independently chosen directions, even when this makes it return to its starting square. It can make the first step as jump, when it chooses to do so. So it can:

• Jump directly to the second square in any direction,
• Annihilate any opponent standing diagonally next to it, without moving (formally one step, and then a step back),
• Annihilate any opponent standing diagonally next to it, moving on to an empty square diagonally next to that ('hit and run'),
• Annihilate any opponent standing diagonally next to it, and normally capture an opponent standing diagonally next to that ('double capture'),
• Stay in place without capturing anything if one of the diagonally neighboring squares is empty (effectively passing a turn)

In other words, the Free Eagle is a Queen enhanced by the diagonal moves of a Lion.

Soaring Eagle and Horned Falcon

The Soaring Eagle and Horned Falcon move as Queen, except that in some directions they do not slide, but have a 'stinging' move, which can:

• Move to the first or jump to the second square,
• Jump to the second square, annihilating an opponent on the first square,
• Annihilate an opponent on the first square without moving (formally one step, and then a step back),
• When the first square is empty, move there and step back (effectively passing the turn).

They can do any of this while capturing an opponent on the final square, or when moving to an empty square. The Horned Falcon does this only straight forward, and the Soaring Eagle in the two diagonally forward directions.

Prince

The Drunk Elephant promotes to a Prince, which is basically a second King. When you have both the King and the Prince in play, you can afford to let one of them be captured. Only when you are left entirely without royals does the opponent win.

Lance

The Lance, in addition to sliding directly forward, can slide up to two squares directly backward.

Knight

The Knight makes a (1,2) leap in any direction (rather than just the two forward-most directions).

Iron General

The Iron General steps one square diagonally forward or directly backward (rather than stepping only in the forward directions).

Pawn

The Pawn occurs in its Shogi form, moving as well as capturing one square directly forward.

Rules

Deciding who moves first

A furigoma (振り駒 piece toss) is used to decide who moves first. One of the players tosses five pawns. If the number of tokins (promoted pawns, と) facing up is higher than unpromoted Pawns (歩), then the player who tossed the pawns plays Gote (後手 White) (that is, getting the second move).

The players may also decide who goes first through a game of chance or a mutual agreement.

Sente (先手 Black) moves first, then players alternate making a move. Making a move is required – skipping a move is illegal, even when having to move is detrimental. Play continues until a player's last remaining royal piece is captured, a player resigns, or a draw is declared.

Skipping a turn

The Fire Demon, Vice General, Lion Hawk, Free Eagle, Lion, Soaring Eagle, and Horned Falcon can all skip a turn if at least one adjacent igui or area move square is empty. However, it is illegal for a player to skip two consecutive turns. Note that if a piece promotes without moving, this does not count as skipping a turn.

Promotion

A player's promotion zone consists of the furthest five ranks of the board, at the original line of the opponent's pawns and beyond. The zone is typically delineated on the game board by two inscribed dots. When a piece is moved, if its move starts and/or ends within the promotion zone, then the player has the option to promote the piece at the end of the turn. Promotion is indicated by turning the piece over after it moves, revealing the character of the promoted piece.

The pieces promote as follows:

Because promotion doesn't happen until the end of the turn, multi-capturing pieces that promote have a chance to make a multi-capture before doing so.

The King, Fire Demon, Great General, Vice General, Lion Hawk, and Free Eagle do not promote, nor can already promoted pieces promote further.

Check

When a player’s last remaining royal piece (a King or Prince) is under immediate attack by at least one enemy piece, it is in check. A player who's last remaining royal is in check is not required to remove the the check, but this is almost always the best option, since a player who has no more royal pieces on the board loses the game. If a player has both a King and a Prince in play, that player may sacrifice one of them. A check can be removed in one of three ways, depending on the situation:

• Blocking the check by placing a piece in between the royal piece and the attacking piece
• Capturing the attacking piece
• Moving to a safe square

The King and Prince need not move out of check, and can even move into check, though this is almost always a blunder. If it is not possible for a player who only has a King or a Prince to get out of check, that piece is checkmated and the game is effectively over.

Illegal Move

A player who makes an illegal move loses immediately. Illegal moves include:

• Making more than one move per turn
• Skipping two consecutive turns
• Moving a piece contrary to how its movements are defined

This rule may be relaxed in casual games, where a player can take back the illegal move and make a legal move.

End of the game

A player who captures the opponent's last remaining royal piece (a King or Prince) wins the game.

Checkmate and Stalemate

If a player’s last remaining royal piece is placed in check and there is no legal move that will resolve the check, the checking move is also checkmate, and effectively wins the game.

If a player’s last remaining royal piece is not in check but that player has no legal moves, the game is a stalemate. Stalemate, like checkmate, leads to a win for the stalemating player.

Resignation

At any point in the game, a player may resign and their opponent wins the game.

Draw

There are only two ways for a draw to occur - 千日手 sennichite (repetition) and impasse.

Repetition Draw 千日手 sennichite - If the same game position occurs four times with the same player to move, then the game ends in a draw, as long as the positions are not due to turn-skipping violations.

Impasse – If neither player can hope to force checkmate or stalemate on the other player’s last remaining royal piece or gain any further material through a series of legal moves, the players may agree to a draw.

Notes

Similar Games

• Mitsugumi Shogi
• Hook Shogi
• Shoko Shogi

Computer Play

You can play Suzumu Shogi online with Game Courier.

Backstory

When I first came across Tenjiku Shogi via Wikipedia back in 2017, I decided to use some of the piece names when I first came up with Shosu Shogi. When I came across H. G. Muller's Interactive Diagrams page, I began messing around with it and creating diagrams of some of my own games. Eventually, I came across images of some of his Mnemonic pieces (I had been looking for images of just the pieces without them being a board for a while at that point) thanks to his CVP page on Chu Shogi. Shortly after that, I started using those pieces to create an interactive diagram for my own version of Tenjiku Shogi. After some experimenting with moves for the Fire Demon and the jumping Generals, I settled on a set of moves that I deemed suitable at the time. I decided to name the game Suzumu Shogi (進将棋 suzumu shōgi, literally "advance shogi," but meant in the sense of "hexadecimal shogi") after looking up Japanese translations of the word hexadecimal. However, I then realized that the setup had problems and then spent way too long trying to fix them, because I wanted the setup to be as close as possible to Tenjiku without any unfair advantages. Shortly after I settled on a suitable initial position, the diagram received an update allowing for more than one locust capture, and I reverted the setup to its original version, strengthened the Fire Demons, Heavenly Tetrarches, and jumping Generals to make the game go faster. After testing these new peices, I implemented restrictions to keep their abilities under control, bringing an end to this game's development at long last.

Thoughts on the Initial Position

The initial position of Suzumu Shogi is well designed: the Fire Demons in their 'boxed-in' initial positions cannot be attacked by jumping Generals (which would be a winning trade, as a Fire Demon is worth at least 3 such pieces), because the shield of jumping Generals in front of them would be able to capture any such jumping attacker. Furthermore, trading these generals aids in the opposing Fire Demon's development, as the recapture plus a Pawn move will then be enough to break the enclosure and allow the Fire Demon to escape into the open when it would be attacked on the next move. Even if the opposing Fire Demon could be threatened before it had time to escape, this weakness is easily defended. Furthermore, trading a jumping General for another jumping General and the Pawn in front of it makes this even worse, as then the opposing Fire Demon doesn't need an extra move to escape into the open. The initial setup has almost all Pawns protected from a distance, so that they are protected from Fire Demon capture (which would immolate two contact protectors at the same time). Only the Pawns in front of the Rooks are an exception, but these can be protected in a single move by withdrawing the Bishop to the 'hole', so that the Chariot Soldier behind it gets a clear view on that Pawn. So despite the immense tactical power of Fire Demons and jumping Generals, the initial position is tactically quiet.

Thoughts on the Opening

Since the jumping Generals cannot threaten an early smothered mate, the greatest threat to White's camp in the early opening is the Great General doubling up with a Rook General to capture a boxed-in Fire Demon before it can escape into the open. However, if Black threatens one of the Fire Demons along a file in this manner, after White exchanges his Rook General for Black's Great General, White can interpose his Great General or Vice General to block Black's Rook General, and the range capture rankings keep White's Fire Demon safe from capture. Because of this and the fact that two Pawns along a diagonal severely hampers the jumping Generals, the opening is slower and more methodical, but can turn into a more Tenjiku-like opening fairly quickly.

Thoughts on the Pieces

Suzumu Shogi has an unusually high concentration of multi-capturing pieces (15 out of 78, which skyrockets to 27 out of 78 with all pieces promoted!). Even Tenjiku Shogi, the game with the next highest concentration of multi-capturing pieces, doesn't have this many (9 out of 78, which increases to 17 out of 78 at most). One might think that this would turn the game into a slugfest between the most powerful pieces on the board, but this couldn't be further from the truth. Of all the multi-capturing pieces, only the Fire Demons can multi-capture on a regular basis thanks to their burning moves. The rest of the multi-capturing pieces are much more limited in how they can use their multi-capturing abilities. The Heavenly Tetrarches can only appear via promotion, so by the time one shows up, the game is close to being finished. The jumping Generals can only travel to occupied squares when multi-capturing, and cannot change direction while doing so, making them vulnerable to recaptures. These pieces are further restricted by the range capture rankings, limiting their effectiveness against each other. The pieces with Lion moves can move to empty squares and change direction mid-move, and are not subject to any movement restrictions, but Lion moves are only effective at short ranges. Thanks to these limitations, the game is surprisingly well-balanced, while also not being too slow.

During the opening, the jumping Generals are in some ways even more dangerous then their Tenjiku counterparts, despite being significantly weaker. Although they cannot threaten an early smothered mate in the opening, they can threaten to leave a gaping hole in the opponent's defenses, and even capture valuable pieces in the process. And since the Fire Demon is also much weaker then its Tenjiku counterpart, this is an effective way to combat it. However, the opponent is far from defenseless against range captures. Since the jumping Generals can only jump two pieces at most, two Pawns in a diagonal line are often enough to defend against early range capture threats against more valuable pieces. But as the board thins, threats from range captures, burns, and promotions become much more credible, thus keeping the game moving.

The Lance and Iron General are slightly stronger versions of their Tenjiku counterparts. The Iron General can't attack all three squares in front of it, but it is no longer limited to a fraction of the squares on the board. Similarly, the Lance can move backward, allowing for slightly better defense of promotion squares on the edge. The Knight, on the other hand, is much stronger and much more flexible in Suzumu Shogi, being able to make a (1,2) leap in any direction. Thanks to this, it has offensive and defensive properties, but it is likely best used as part of the King's castle, where it can use its jumping abilities to protect other pieces from burning moves.

Last revised by A. DeWitt.