Nearlydouble Hex Chess

As many games vie for the title of hex analogue to FIDE Chess I selected the two that I judge most internally consistent, Wellisch and McCooey, along with my own attempt at that goal, the non-Aurochs form of Trios Hex Chess. All arrange 91 hexagonal cells in a larger hexagon of constant side 6, and constant-side hex boards seem the most suited to having both 2-player and 3-player versions of games. Contrast boards with three sides each of two lengths, such as my admittedly extreme 3 Player Dabbaba Qi, which suit 3 players but not 2, or with four sides of one length and two of another, which suit 2 but not 3 - let alone less regular shapes such as Fool's Hexagonal Chess, another good FIDE analogue. Sticking with six equal sides of length 7, 8, and 9 cells gives 127, 169, and 217 cells respectively. 169 proves quite an apt number as not only, like 91, a multiple of 13, but the last multiple of 13 before 182, which is twice 91. So it is short of double the original number by a factor of that number. The resulting increase in piece density is, I contend, worth it for the simplicity of the board - and even allows ND Wellisch a decent 2-player form, which Wellisch Chess itself seems not to have had. It occurs to me that my hex version of my 3-player "distorted squares" variant Fiancé Chess, originally added here as Fiancé also has enlarged numbers of minor pieces, is better suited to the Stelliform layout.

As square-cell ND variants enhance the Knight to Catapult by adding the 3:0 leap, so I add the move completing the hexagonal pattern of destinations comparable to the diamond pattern of square cells. See Chinese perimeters in the Trios Hex Chess notes for more detail on these patterns - 3:0 in the McCooey case, 2:0 in the Wellisch case. The latter removes an un-Knightlike binding - as my Trebuqi intentionally does - but I still double the original 3 aside to 6. As hex Knight analogues are not colourswitching, preserving this is not an issue here as it is in square-cell games. It is to avoid the question of what to do with longer leapers that I do not consider the Aurochs form of Trios Hex.

Since originally posting this page I have also deployed symmetric hex pieces in the same numbers as here, though with many fewer forward-only pieces, on a radically different and smaller board in Hourglass Hex Chess.

Setup

ND Wellisch

ND McCooey

ND Anglojewish

ND AltOrth

ND Trios, 2-player only

The two armies shown in the first can also, if the piece at each end of each third rank is removed, be played against two ordinary (non-Nearlydouble) Trios Hex Chess armies in a four-player different-armies variant.

Pieces

Square-cell piece	Wellisch analogue	McCooey analogue	Anglojewish analogue	Altorth analogue
Pawn	POINT	BROKER	BROKER	MIGRANT
	Always moves one cell orthogonally forward. The Wellisch board has two forward orthogonals, making a divergent piece unnecessary. A standard piece (with just the one orthogonal) in Xiang Qi and Shogi.	Moves along the one forward orthogonal except when capturing, which it does along either forward hex diagonal.	As McCooey	Moves along the one forward orthogonal except when capturing, which it does along either half-forward orthogonal.
Rook	ROOK	ROOK	FINCH	FOREROOK
	Moves any distance through empty cells along any orthogonal, as FIDE and Xiang Qi but with more orthogonals.	As Wellisch	As Rook, but turns 60° left or right (but not both in one move) at each step.	As Rook, but only on the straight forward and both half-backward orthogonals.
Catapult	VICBABA	SEIOPELMA	SEIOPELMA	VICBABA
	Moves one step along any hex diagonal, or leaps two steps along any orthogonal, cannot be blocked.	Makes any root-seven leap, or leaps three steps along any orthogonal, cannot be blocked.	As McCooey	As Wellisch
Bishop	N/A	UNICORN	RABBI	HINDROOK
		Moves any distance through empty cells along any hex diagonal. Bound to 1 in 3 cells and so 3 aside in the original, hence 6 here.	As Unicorn, but turns 60° left or right (but not both in one move) at each step.	As Rook, but only on the straight backward and both half-forward orthogonals.
Queen	VICEREINE	DUCHESS	COHEN or KOHEN	ROOK
	Moves as Rook or one step along any hex diagonal.	Moves as Rook or Unicorn.	Moves as Finch or Rabbi.	As Wellisch Rook above
King	GENERAL	GRANDDUKE	GENERAL	GENERAL
	Moves one step along any orthogonal. Must be kept out of Check. A standard piece in Xiang Qi.	Moves one cell along any orthogonal or hex diagonal. Must be kept out of Check.	As Wellisch	As Wellisch

Rules

The following pieces have an optional double-step initial move:
Points starting on the 2nd rank;
all Brokers and Migrants in non-Trios games;
Brokers and Migrants starting behind others of their kind in Trios games.
Migrants making a capturing move to the starting cell of an allied Migrant retain this option if, but only if, the one starting there also had it. This is the case whether the latter Migrant made that move itself, made a single-step move, or was captured unmoved.
All can be immediately captured En Passant by enemy pieces of the same kind, regardless of where the enemy piece starts.

Castling does not suit the original variants, but rearranging the pieces for 169 cells makes it viable in ND McCooey and ND Trios. A Grandduke and any Rook on the same edge, both previously unmoved, pass each other along the same orthogonal, to finish on the Unicorns' starting cells. The Grandduke's cell and both Unicorn ones must not be in Check. All intervening cells must be empty. Castling with ND Trios non-edge Rooks is not allowed.

Forward-only pieces reaching a cell whence they have no further move must be promoted, to any of the same variant's other capturable pieces.

In 2-player subvariants Check, Checkmate, and Stalemate are as usual. In the 3-player ones a player is Checkmated when their General or Grandduke is threatened by the player about to move. That player's pieces are removed from the game, which continues with the Checkmating player's move.

To 2-player Nearlydouble Wellisch can be added two original - non-Nearlydouble - McCooey armies at the empty corners to give a 4-player variant. The non-Nearlydouble Wellisch army has never been up to taking on later hex armies, but I contend that this one can do it.

Notes