The Chess Variant Pages



This page is written by both of the game's inventors, Antoine Fourrière and Roberto Lavieri.

Symmetron! 112

By Antoine Fourrière and Roberto Lavieri

 

Introduction

Symmetron! 112 is a large version of Symmetron! 44, which is a competing entry in the current 44-square contest.

Its main characteristics are:

  • Several pieces can change to their "hippogonally symmetrized" version (that is, turning their orthogonal moves into diagonal moves and vice versa), but through different mechanisms.
    There is a piece in Symmetron! which has the ability to change the movement of some adjacent friendly pieces to a symmetrized type: the SHS, or Self-Hippogonal-Symmetrizer. When one-or-two-square distant to the friendly SHS, an Advancer-Rook changes automatically its movement to that of an Advancer-Bishop, and a Dragon-Bishop movement changes to Dragon-Rook. (We prefer these terms to Dragon-Horse and Dragon-King.) This is automatic symmetrisation by adjacence, in this case, adjacence to a SHS.
    The Pawns and Bawns have a natural symmetrization by capture, They have another symmetrization available, they can change into each other when adjacent to a friendly SHS. This is permanent symmetrization by adjacence.
    The King moves according to position. Inside its nine-square Palace, it moves one step orthogonally, but outside its Palace, the King's move changes to the symmetrized type, one step diagonally. This is symmetrization by position.
    The Can(n)on is a flip piece. At the end of its move, it becomes - or stays - a Xiangqi Cannon, or its diagonal equivalent, a Canon. It may also flip without moving. Before its first flip, the Can(n)on is set to move Rook-wise. This is optional symmetrization after moving, or as a move.
    Of course, the Slip-Nightrider is already symmetrized.

  • Each Player has a Launching Square, which is accessible only to the Reducer, the SHS, the Resurrector, or the other pieces when they change owner, Shogi-like, because they are one-or-two-square distant to the capturer's Resurrector.

 

Board and Setup

The 112-square Board is composed of a 10x11 rectangle or Arena, plus two Launching Squares (one for each player, as in Pocket Mutation Chess).

White
King (K): f1
Reducer (R): a2
SHS (H): k2
Resurrector (U): WLS
Dragon-Bishops (DB): b2 j2
Advancer-Rooks (AR): d2 h2
Slip-Nightrider (SN): a1 k1
Cannon (C): b1 j1
Pawns (P): a3 b3 c3 i3 j3 k3
Bawns (B): d3 e3 f3 g3 h3
Black
King (K): f10
Reducer (R): k9
SHS (H): a9
Resurrector (U): BLS
Dragon-Bishops (DB): b9 j9
Advancer-Rooks (AR): d9 h9
Slip-Nightrider (SN): a10 k10
Cannon (C): b10 j10
Pawns (P): a8 b8 c8 i8 j8 k8
Bawns (B): d8 e8 f8 g8 h8

Pieces

Pawn

 

The Pawn moves one or two steps forward or one step sideways and captures one step diagonally forward. When one-or-two-square distant to the enemy Reducer, it is only allowed a one-step move, unless it is also one-or-two-square distant to the friendly Reducer. If one-or-two-square distant to the friendly SHS, the Pawn can change as a move to a Bawn. There is no en-passant.

Bawn

 

The Bawn moves one or two steps diagonally forward and captures one step forward or sideways. When one-or-two-square distant to the enemy Reducer, it is only allowed a one-step move, unless it is also one-or-two-square distant to the friendly Reducer. If one-or-two-square distant to the friendly SHS, the Bawn can change as a move to a Pawn. There is no en-passant.

Cannon

 

The Cannon is the orthogonal form of the Can(n)on, which is a flip piece. At the end of its move, it stays a Xiangqi Cannon, or becomes its diagonal equivalent, a Canon. It may also flip without moving. (Before its first flip, the Can(n)on is set to move Rook-wise.) When one-or-two-square distant to the enemy Reducer, it is only allowed a neutral Wazir's move, unless it is also one-or-two-square distant to the friendly Reducer. Cannons are unaffected by the SHSs.

Canon

 

The Canon is the diagonal form of the Can(n)on, which is a flip piece. At the end of its move, it becomes a Xiangqi Cannon, or stays its diagonal equivalent, a Canon. It may also flip without moving. (Before its first flip, the Can(n)on is set to move Rook-wise.) When one-or-two-square distant to the enemy Reducer, it is only allowed a neutral Wazir's move, unless it is also one-or-two-square distant to the friendly Reducer. Canons are unaffected by the SHSs.

Slip-Nightrider

 

The Slip-Nightrider moves and captures with an odd number of Knight moves (usually one or three) in the same direction. When one-or-two-square distant to the enemy Reducer, it is only allowed a Knight's move, unless it is also one-or-two-square distant to the friendly Reducer. Slip-Nightriders are unaffected by the SHSs.

Advancer-Rook

 

The Advancer-Rook slides any number of empty squares along a row or column. If there is a capturable enemy piece adjacent to the landing square and in the same direction of its path, this piece can be OPTIONALLY captured. When one-or-two-square distant to the friendly SHS, its movement changes automatically to the movement of an Advancer-Bishop. When one-or-two-square distant to the enemy Reducer, it is only allowed a one-square move, unless it is also one-or-two-square distant to the friendly Reducer.

Dragon-Bishop

 

The Dragon-Bishop slides any number of squares diagonally, or one square orthogonally. When one-or-two-square distant to the friendly SHS, its movement changes automatically to the movement of a Dragon-Rook. When one-or-two-square distant to the enemy Reducer, it is only allowed a one-square move, unless it is also one-or-two-square distant to the friendly Reducer.

Reducer

  The Reducer can move with a one-step non-capturing movement, or from the Board to its own Launching Square and vice versa, to a square on the four central ranks. A Reducer can explode as a move with the enemy Reducer when both Reducers are orthogonally adjacent. It cannot capture, or be captured by, any other piece. The Reducer has the ability to reduce the movement of any enemy rider, slip-rider or hopper (in Symmetron! 112, a Dragon-Bishop or an Advancer-Rook, symmetrized or not, a Can(n)on or a Slip Nightrider) which is at a distance of one or two squares (that is, at a King's move, an Alfil or Dabbabah's move, or a Knight's move) to its otherwise permitted one-unit moves (that is, a Slip-Nightrider is still allowed to move as a Knight). If its own Reducer is also one-or-two-square distant to a rider, slip-rider or hopper, that rider, slip-rider or hopper is not reduced.

SHS

  The Self-Hippogonal-Symmetrizer, or SHS, can move with a one-step non-capturing movement, or from the Arena to its own Launching Square and vice versa, to a square on the four central ranks. A SHS can explode as a move with the enemy SHS when both SHSs are orthogonally adjacent. It cannot capture, or be captured by, any other piece. The SHS turns the moves of some friendly pieces which are at a distance of one or two squares (that is, at a King's move, an Alfil or Dabbabah's move, or a Knight's move) in their hippogonally symmetric equivalents, but the Can(n)on remains unaffected. Thus, an Advancer-Rook and a Dragon-Bishop one-or-two-square distant to their SHS move as an Advancer-Bishop and a Dragon-Rook. A Can(n)on or a Slip-Nightrider one-or-two-square distant from its SHS is not affected, but a Pawn or Bawn one-or-two-square distant to its SHS has the option of changing into a Bawn or Pawn. SHSs are immune to the Reducers.

Resurrector

  The Resurrector can move with a one-step non-capturing movement, or from the Arena to its own Launching Square and vice versa, to a square on the four central ranks. A Resurrector can explode as a move with the enemy Resurrector when both Resurrectors are orthogonally adjacent. It cannot capture, or be captured by, any other piece. The Resurrectors allow the Shogi-like retrieval of the "non-magic" enemy pieces which are captured at a distance of one or two squares (that is, at a King's move, an Alfil or Dabbabah's move, or a Knight's move), but the Reducers and SHSs remains unaffected. Thus, when an Advancer-Rook, a Dragon-Bishop, a Slip-Nightrider, a Can(n)on, a Pawn or a Bawn is captured at a one-or-two-square distance of the capturer's Resurrector, the captured piece is brought back on the Launching Square of the capturer, provided that Launching Square was free. (Otherwise, the captured piece is removed from the game as usual). The retrieved piece may be parachuted as a move on the four central ranks. Resurrectors are immune to the Reducers.

King

  The King moves and captures with a single orthogonal step in its own Palace and a single diagonal step elsewhere.

There is no castling.

 

Rules

There are two ways of winning the game: to checkmate the opposing King, or to reduce the enemy pieces to only four.

Stalemate or triple repetition is a draw.

A Pawn or Bawn on the tenth row promotes into a Dragon-Rook, an Advancer-Bishop, a Slip-Nightrider, or a Can(n)on.