Seireigi

Seireigi (精霊棋 seireigi, "spirit's game") is a Shogi variant that was conceived from wanting to create a game that could be played with standard Chess equipment while also reducing the importance of material advantages. While I wasn't able to make a game that fulfilled those criteria, I was able to do the next best thing - a variant of standard Shogi that resembles an earlier work of mine, Shosu Shogi, while better executing the promotion ideas from that game, by using movesets that play into Shogi's drop mechanic (Many thanks to H. G. Muller for helping me with this).

Rules PDF for playing Seireigi over-the-board

Play Seireigi with others or against an AI via the Ludii Player

• Click here to download up-to-date ludemes

Play Seireigi with others or against an AI via Jocly

• Jocly implementation by François Houdebert and H. G. Muller

Play Seireigi against others via Game Courier

Setup

Seireigi uses the same equipment as Shogi, except the back-rank promotions are different. Nevertheless, the game can be played with standard Shogi equipment, with the blank sides of the Gold Generals representing their promoted forms.

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 pieces are enlarged versions of H. G. Muller's Mnemonic pieces. The Shogi pieces used in the diagram and the Pieces section are from Eric Silverman's 1kanji set, which were originally made for use in Stephen Tavener's Ai Ai. The Chess-like images are from Bob Greenwade's graphics set for the Seireigi games.

Pieces

The following table shows the moves of the pieces. XBetza notation is included for easier reference.

Piece		Promoted Piece
King 王将/玉将 ōshō/gyokushō	The King moves one space in any direction, but not into check. (K)	The King does not promote.
Rook 飛車 hisha	The Rook moves as it does in Chess - it slides orthogonally. (R)	Dragon King 龍王 ryūō	The Dragon King moves as it does in Shogi - it can move as a Rook or as a King. (RF)
Bishop 角行 kakugyō	The Bishop moves as it does in Chess - it slides diagonally. (B)	Dragon Horse 龍馬 ryūma	The Dragon Horse moves as it does in Shogi - it can move as a Bishop or as a King. (BW)
Gold General 金将 kinshō	The Gold General moves as it does in Shogi - it moves one square orthogonally, or diagonally forward. (WfF)	Great Elephant 大象 taizō	The Great Elephant slides diagonally forward. In addition, it can move one square diagonally backward, sideways, or directly forward. (fBbFsfW)
Silver General 銀将 ginshō	The Silver General moves as it does in Shogi - it moves one square diagonally, or directly forward. (FfW)	Running Wolf 走狼 sōrō	The Running Wolf slides vertically. In addition, it can move one square sideways or diagonally forward. (vRfFsW)
Knight 桂馬 keima	The Knight moves as it does in Shogi - it jumps one square forward and then one square diagonally outward. (fN)	Heavenly Horse 天馬 temma	The Heavenly Horse can step one square in any diagonal or forward direction, jump two squares along any forward direction, or jump one square backward and then one square diagonally outward. (FfWbNfAfD)
Lance 香車 kyōsha	The Lance moves as it does in Shogi - it slides directly forward. (fR)	Free Tiger 奔虎 honko	The Free Tiger can slide sideways, step one square vertically, or jump one square sideways and then one square diagonally outward. (sRvWsN)
Pawn 歩兵 fuhyō	The Pawn moves as it does in Shogi - one square orthogonally forward. (fW)	Tokin と金 tokin	The Tokin moves as it does in Shogi - as a Gold General. (WfF)

Rules

For a full ruleset, click the Rules PDF link at the top of the page.

All rules, unless stated otherwise, are identical to those of standard Shogi.

Board Style

The board may be either a traditional uncheckered Shogi board, or a checkered board with a dark square at each player's left-hand corner.

Notes

Similar Games

• Chu Seireigi
• Dai Seireigi
• Yonin Seireigi

Backstory

When this game was originally conceived, the Knight and Lance used to be boosted with additional step moves in the sideways and backward orthogonals respectively, and the Silver and Gold Generals promoted to Violent Wolf (same as Gold General) and Drunk Elephant (King that can't step directly backward), respectively. The former two were intentionally left constrained so as to not affect the gameplay. However, a comment from H. G. Muller soon popped up that would drastically change Seireigi:

I am not a strong Shogi player, but let me relay a comment from the famous Shogi vlogger Hidetchi, which seems relevant here. Hidetchi once commented on a proposal to let the Gold General promote to non-royal King (I think it was in the now dissolved 81squareuniverse forum). His remark was that that this was pointless, as it should have no significant effect on the game. Shogi is a 'race to mate', where every tempo counts, and dropping a general in the zone, moving it to promote, and then use it to capture something with it (benefitting from the newly acquired moves), takes unaffordably long. The overwhelming majority of dropped generals would never move again for the remainder of the game, and certainly not backward. Typical use is to drop them in front of the enemy King with check, either as a sacrifice to draw it out, or forcing it back, and then drop a new piece with check on a (now protected)  square in front of the dropped general.

To have an impact you would have to add extra forward moves, which could check a King after it evaded the checkdrop. E.g. fR, which sounds very powerful, but since it can happen only in the zone and the other moves of a Gold cannot easily pull it back, in practice only will have very limited forward range, of which the first step was already be reachable by a plain Gold. So it gives you one or two extra (but blockable) moves. If you don't want the promoted piece to be upward compatible, FfR could be a good choice.

Initially, I added Lion moves to the Wolf and Elephant, (this decision being inspired by Great Whale Shogi), but H. G. Muller thought this wouldn't be very helpful, and for good reason, as he explained in a later comment:

It would give the variant much less 'Shogi feel' when you introduce such an exotic move. I am also not sure whether in Shogi Soaring-Eagle-like Lion capture would do really much more than a two-square jump (or even slide). The locust capture is mainly dangerous because it can eliminate protected pieces. But in Shogi the main factor that determines the value of a piece is how effective it is in checking a King. And there you don't care whether it was protected or not. Starting to hunt for other material by dropping, promoting, capturing takes too long, and you would probably be checkmated before you get the opportunity to drop the piece you gained by it.

Because of this, I decided to give the Wolf and Elephant pieces two ranging moves and one less step move than their unpromoted counterparts. Because of these changes, I changed their names to Running Wolf and Great Elephant, respectively. This made the game much more unique, but also made the extra Knight and Lance moves a burden. It made less sense to give them extra step moves when this would only heighten the learning curve, so I reverted the Knight and Lance to their normal Shogi selves.

As for the other two new pieces (the Heavenly Horse and Free Tiger), I initially copied the move of the Promoted Knight from Pocket Shogi Copper over to the Heavenly Horse, and originally gave the Free Tiger a sideways slide and a sideways Knight move. However, I considered the latter move to be a bit too weak, as it only had two forward moves, while every other promoted piece had a move with at least three. To fix this problem, I added a vertical step to the Free Tiger's move. This ensured that every promoted piece had at least three forward moves, thus bringing the Free Tiger more in keeping with the other promoted pieces. After a while, I changed the Heavenly Horse to make it stronger and more unique, since its original move was too similar to the Tokin's move.

Thoughts on the Pieces

Compared with standard Shogi, Seireigi has more moves to remember thanks to the more varied promotions (7 different promotions in total, vs 3 for standard Shogi). However, most promotions simply repeat the themes of their unpromoted counterparts (or are even the same as their Shogi counterparts), which helps to ease the burden of learning their moves. The exceptions are the Running Wolf (Promoted Silver General) and Great Elephant (Promoted Gold General), but both follow a consistent pattern; they lose a step move but gain two sliding moves. This allows the promoted forms of the Generals to have larger influence on the game while still being relatively simple to learn.

The Free Tiger (Promoted Lance) is unusual in another way, as it has the ability to make sideways Knight leaps, something the unpromoted Lance lacks. In fact, this ability is nonexistent in the historical variants when not part of a Lion move. The reason for this unusual move is because I wanted to include in Seireigi all the possible moves that a piece in Shosu Shogi could make (step, slide, or Knight leap in any direction) while having promotions that would make promotable pieces on the back rank lose at least some of their powers upon promotion. So I took the liberty of inventing a new piece to fill the role of having sideways Knight leaps, which is basically just a Marshall that cannot move more than one square in the vertical directions.

vs Shosu Shogi

I wholeheartedly believe that Seireigi is better than Shosu Shogi. In fact, of all my variants, Seireigi is my favorite so far. This is not to say that Shosu Shogi is bad. Both are high-quality games, and Shosu Shogi has some tried and true ideas regarding piece promotions, which Seireigi borrows for its own promotions. However, these ideas are better executed in the latter. In Shosu Shogi, the fact that most promotions keep all their old moves means that there is not much strategy involved regarding piece promotion. In Seireigi, all pieces on the back rank lose at least some of their old moves upon promoting, which gives the game much more strategic depth as a result. But more importantly, Seireigi can be played with a single standard Shogi set. The ability to play a game using a single set of commonly available equipment is a quality that most chess variants, including Shosu Shogi, lack. This a huge plus for Seireigi, as this allows for over-the-board play, which is not an option for most Chess variants without using specialized equipment (especially the large ones).

vs Standard Shogi

It's hard to say which game is better here. Don't get me wrong; I love them both. However, constructive criticism is also important. Shogi has less piece moves to remember, and so would be better as far as the learning curve, as all the back rank promoting pieces promote to Gold General and the actual Gold Generals do not promote. However, Seireigi makes up for this by making most promotions repeat the theme of their unpromoted counterparts and making those that don't follow a consistent pattern, so this disadvantage is quite diminished in practice. I'd also say that because of the larger variance in piece types, Seireigi is better when it comes to avoiding draws due to an Entering King, as well as allowing for more decisive endgames involving promoted pieces. In Shogi, if a lot of Gold equivalents appear on the board, the game becomes slow and tedious. After all, it is difficult for a piece to successfully attack another piece that moves just like itself. However, in terms of overall quality, both are pretty evenly matched.

Last revised by A. M. DeWitt.