Whack Chess

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Whack Chess
Designed by Matthew Rogers
Chess with stacking pyramids and a dynamic board
:Players Players: 2 - 2
:Time Length: Long?
:Complexity Complexity: Medium
Trios per color: 4
Number of colors: 4
Pyramid trios:
Monochr. stashes: 4
Five-color sets: 4
- - - - - - Other equipment - - - - - -
Chessboard wedges, dice
Setup time: 5 minutes
Playing time: 20 minutes
0.333 Hr
- 100 minutes
1.667 Hr
Strategy depth: High
Random chance: Medium
Game mechanics: chess, dynamic board
Theme: chess
BGG Link:
Status: complete? (v1.0), Year released: 2987

Whack Chess uses some of the mechanics of Stack Chess and some of the mechanics of Martian Coasters, all played on Eeyore's Martian Chessboard wedges.

These rules assume familiarity with the rules of modern chess, but see the External Links below for any questions in that regard.


Each of the two players needs two stashes of pyramids to construct their pieces. A player can use two stashes of the same color, but a "Fire and Ice" arrangement (i.e. red/yellow versus black/blue -- nomenclature taken from Pyrinoes) is attractive and effective.

  • A pawn (p) is any unstacked 1-pip pyramid.
  • A knight (N) is any 2-point stack (i.e. a lone 2-pip pyramid or stack of two 1-pip pyramids).
  • A bishop (B) is any 3-point stack.
  • A rook (R) is any 4-point stack.
  • A king (K) is any 5-point stack.
  • A queen (Q) is any 6-point stack.
  • No stack may exceed 6 points worth of pieces.

Stacks must never involve nesting; i.e. pyramids may only be placed on other pyramids of the same size or larger.


An example of board setup

Each player begins with two chessboard wedge sections. Fire (White) places one section in the center of the table in any orientation. Ice (Black) places another so that it joins the first at one same-sized edge. Fire places the third so that it joins one of the others (and only one) at a same-sized edge. Ice places the last so that it joins an "end" section (i.e. not the one that already has two joined edges) at a single same-sized edge. The result should be a sort of "track" four spaces wide, which may turn along its length. Ice sets up pieces in the last section placed, and Fire sets up in the section at the opposite end of the track. (Note: This linear arrangement is only for initial setup, the board can and should transform during play in ways that create more consolidated fields.)

A Fire player's pieces set up to begin

The initial pieces for each player are a conventional chess inventory thus:

  • 8 pawns (1-pip pyramids)
  • 2 knights (each a single 2-pip pyramid)
  • 2 bishops (each a single 3-pip pyramid)
  • 2 rooks (each a stack of two 2-pip pyramids)
  • a king (two 1-pip pyramids stacked on a 3-pip)
  • a queen (a stack of three 2-pip pyramids)

Set up the rank at the end of the track as four pawns, the next as bishop-rook-king-bishop, then knight-queen-rook-knight, then the other four pawns:

p p p p
p p p p

Once the pieces are on the board, Ice rolls a die to modify the board according to the dynamic board schedule.

A different example after the first board transformation (a TIP): Note that the section with Fire pieces has rotated so that it connects along the pNBp file, instead of the pppp rank.

Dynamic Board Schedule

Roll a die (conventional d6 or Treehouse die) and consult this table:

  • Before the first move of the game, AND
  • After each capture.
Whack Chess Board Rolls
d6 Treehouse Result
1 TIP Move any section to a place where it will only connect by one edge. If no such move is possible, the board stays the same.
2 AIM Separate the board into two sub-boards of two sections each. Rotate one of the sub-boards, and rejoin the two sub-boards.
3 DIG Move any section to a place where it will connect by two or more edges. If no such move is possible, the board stays the same.
4 SWAP Swap any two sections; orientation is determined by corner angles. (I.e. the wide and narrow angles of the wedge should be put in the same relative positions as those of the wedge for which it is swapped.)
5 HOP No change to the board.
6 WILD Move any one section so that it connects with the rest of the board by the same-sized edge(s).

Further notes:

  • Each section has two long and two short edges. Sections can only join by same-sized edges.
  • All pieces stay in place on the moving chessboard section(s).
  • No section may be moved so that the board is separated into entirely disconnected areas.


If Ice moves a board section as a result of the first roll, then Fire makes the first move. But if Ice fails to move a board section, then Fire rolls. Rolling continues until a player actually moves a board section, after which the other player moves the first piece.

Play alternates with one piece moved by each player, as in modern chess. Pawns move any direction--a single space orthogonally, or diagonally to capture. Other pieces move as in modern chess. There is no castling.

Pieces may combine by moving onto a same-sized or larger piece of the same side, as in Stack Chess. Pawns move orthogonally, not diagonally, to combine. The resulting piece is determined by its total pip value. Stacks with more than six pips total are forbidden. (Pieces may NOT "split.")

Pieces capture by moving on to the space occupied by an opposing piece, as in modern chess. AFTER ANY CAPTURE, the capturing player rolls a die to change the board, according to the table above.

Note that exotic circumstances appear on the diagonals leading to a filled juncture of three or five section corners. In the triangular setup for Martian Chess, pieces traveling these diagonals are (appropriately for that game) allowed to continue along their choice of the diagonals that radiate from the juncture -- turning 60 degrees left or right onto the next section as the case may be. But in Whack Chess, it is necessary for a bishop or queen (the only pieces to which this rule applies) to stop as though it had reached an external edge of the board. The piece may move along any diagonal leading from the space on a subsequent turn.


A player should declare "check" whenever one of his pieces directly threatens (one of) the opponent's king(s). It is illegal to move into check, to discover check on one's own king (i.e. to move a piece that is pinned against the king), or to move a board section so as to place one's own king in check.

Unlike modern chess, kings may (must!) be captured.

A player wins when all the opponent's kings are eliminated at the end of the player's turn.

Either player may resign at any time.

A draw is forced if a player is not in check but has no legal move, or if there is an agreed prospect of perpetual check, or if the two sides are each reduced to eight points or less total remaining material.

External Links