Aquachess

Start on the ocean's surface. Imagine a battle taking place there between two great navies.

Now imagine that the combatants can call upon creatures of the sky and sea to give their aid.

That's the concept behind Aquachess.

Setup

The setup for Aquachess is on three standard 8x8 chessboards, ideally situated one above the other.

The three boards represent the Sea (bottom), the Waves (middle), and the Air (top). In the diagrams below, they're colored differently, since most pieces are restricted to one or two levels; the colors can make it easier to tell what level is being discussed. The three boards you use may be colored the same way, all the same, or something else entirely, as you prefer (and according to what's available).

If you have access to a Stratochess game or something similar, that's suitable. The three boards should all be oriented the same way (white corners to the players' right). Short of that, it's perfectly acceptable to just put three regular boards side-by-side. I recommend putting the Sea to White's left and Air to White's right, but you can place them however you prefer.

Sea (Level 1)

From the outer edge inwards, each side sets up with an Octopus, Seahorse, Swordfish, and Manta in the first row, and a Jellyfish and Crab in the second, with four Fish between the two Crabs.

Waves (Level 2)

On the Waves, the King, Queen, and Pawn go in their usual spots on a chessboard. The Bishop, Knight, and Rook are replaced with the Ship, Dolphin, and Whale, respectively.

Air (Level 3)

In the Air, the Dragon is placed above the King, and the Sphinx above the Queen. Outward from those two are the Falcons, Ravens, and Griffins.

In the second row, from the center outward, are the Geese, Pegasi, and two Sparrows (totaling four).

Pieces

The King, Queen, and Pawns all carry over from standard Chess, but there are also many fairy pieces involved. Some of these are taken (though most of them are modified to allow movement between Levels) from other games, both historical and modern, while a few are entirely new.

Sea Pieces

Crab: The Crab can move and capture like a limited Knight: either two spaces forward and one space sideways, or one space back and two spaces sideways. It stays in the Sea.

Fish: The Fish  moves exactly like a Pawn, except that it can also move (without capturing) one space directly backward.

(Borrowed from David Moeser's Fish Chess.)

Jellyfish: The Jellyfish moves one space in any direction, but stays in the Sea. It cannot capture, but any enemy piece in a neighboring space, including the one directly above it on the Waves, is immobilized.

As a courtesy, when a Jellyfish is moved to a place that immobilizes an opponent's piece, especially if if affects a piece on the Waves, the player should notify the opponent. A courtesy warning might also be in order if the opponent moves a piece on the Waves to the space where it would be immobilized.

(Essentially a modified Immobilizer, moving like a King instead of a Queen.)

Manta: The Manta slides one or two spaces diagonally, always staying in the Sea. It can also "rifle capture" (that is, capture without moving) into a neighboring orthogonal space, or the space directly above it.

Octopus: The Octopus moves one square diagonally, then jumps two or more squares orthogonally; moves one square orthogonally, then jumps two or more squares diagonally; or can switch between the Sea and Waves either vertically or to any neighboring square.

(Borrowed from Charles Daniel's Octopus Chess.)

Seahorse: The Seahorse moves around the Sea like a Knight in standard Chess, but does not jump -- it must be able to move to its destination with one orthoganal and one diagonal move (in either order).

Swordfish: The Swordfish can move up to 2 spaces in any direction, or move between the Sea and Waves levels going 1 space diagonally.

Waves Pieces

For purposes of envisioning the action, the King, Queen, and Pawns can be thought of as each having their own small ship. (If it helps, refer to the Ship as the Warship.) Accordingly, they all stay on the Waves.

Dolphin: The Dolphin can leap up to 3 spaces orthogonally, and can move between the Waves and Sea by moving 1 space orthogonally. If it's capturing, it cannot leap.

Ship: The Ship moves one square diagonally, then like a Rook either forwards or backwards away from its starting point.

(Borrowed from Jean-Louis Cazaux's Tamerlane II.)

Whale: The Whale can move straight forward, straight backward, or backward diagonally, an indefinite number of spaces. It can move from Waves to Sea on the first step of the move, or from Sea to Waves on the last.

(Borrowed from Chu Shogi.)

Air Pieces

Dragon: The Dragon is the only piece that can move on all three Levels. It moves like a Bishop, but the first space or two can also be used to switch Levels before it (optionally) continues along its path. It can also move one space orthogonally, optionally moving one level up or down as it does so.

(Loosely based on the Dragon from Gary Gygax's Dragon Chess.)

Falcon: The Falcon moves forward diagonally like a Bishop, or directly backward like a Rook. At any point along this path (but only once per move) it can switch between Air and Waves.

(Borrowed from Karl Schultz's Falcon-Hunter Chess.)

Goose: Leaps 2 spaces diagonally forward or 2 spaces directly backward, or moves 1 space in any of those directions while moving between Air and Waves.

(Borrowed from Tori Shogi.)

Griffin: The Griffin moves one space diagonally, optionally switching between Air and Waves as it does so, then continues orthogonally like a Rook away from the starting point.

Pegasus: Like the traditional Nightrider, the Pegasus makes one or more Knight move in a straight line; or it can move between the Air and Waves with a single Knight's move.

Raven:  The Raven moves like either a Rook or Nightrider on the Level it's on, or can move between Air and Waves vertically or to an adjacent space (including diagonal).

Sparrow: Moves like a Queen on the Level it's on, but can only capture in adjacent spaces. It can also move, capturing or not, between Air and Waves either vertically or to an adjacent space.

Sphinx:  Moves like a Queen or Knight (like an Amazon). If it's using a Queen's move, it can switch between Air and Waves with either the first space, the last space, or both.

Rules

Notwithstanding the above, the only rule from standard Chess that isn't used here is Castling, since the Rooks are replaced by the Whales.

Fish as well as Pawns are capable of En Passant.

Notes

Note that, despite its slow movement and inability to capture on its own, the Jellyfish is potentially a very powerful piece. Working with any other piece -- especially a Knight -- it can force a quick Checkmate, by immobilizing the King while the other piece attacks. The opponent's only option then would be to block or capture the other piece, and if that cannot be done, the player wins.

It's also noteworthy that the Pegasi start out in good position to capture the opponent's Falcons on their first move. However, those pieces are heavily guarded, so doing so may be regrettable.

(And if a Dragon captures a Goose, it's perfectly OK to declare that the Goose is cooked.)

Borrowing Pieces

With so many pieces "borrowed" from other variants in this game (most with 3D aspects added), I thought others might want to "borrow" some of the original pieces (with 3D aspects removed). Here's what I have with the XBetza notation for the ones that stand out (to me) as being unlike anything found elsewhere:

Manta: B2cabW

Seahorse: nN

Sparrow: mQcK

The Jellyfish is just K with the added quality that it Immobilizes all enemy pieces in adjacent squares (which isn't represented in XBetza).

Last revised by Bob Greenwade.