This game was invented by Robert Abbott in 1963. It was originally called Crossings and was first published in 1969 in [GG]. At that time, the game took place on a board of 8 rows by 8 columns. When it was revised and published in 1975, it was renamed Epaminondas, the Theban general who invented the phalanx and used it to defeat the Spartans in 371 BC

Material: A square board with 12 rows by 14 columns. 28 White pieces and 28 Black pieces.

Definitions: Phalanx – A phalanx consists of a line of one or more adjacent pieces of the same color (either orthogonally or diagonally).

Rules: A phalanx moves along the line that defines it, a maximum distance equal to the number of pieces that constitute it (for example, a phalanx of four pieces can move up to four squares).

If the phalanx, while moving, encounters an enemy phalanx consisting of fewer pieces, this second phalanx is captured. The phalanx stops, leaving the first piece on the square where the first piece of the enemy phalanx was located. In all other cases, the phalanx can only move on empty squares.

Capture is not mandatory.

Movement – On their turn, each player moves one of their phalanxes.

Objective: The player who, at the beginning of his turn, has the most pieces on his last row wins (for example, if White, before playing, has three pieces on the 12th row and Black has two pieces on the 1st row, then White has won the game).

Notes: An isolated piece is a phalanx of dimension one, and can move to any adjacent square (either orthogonally or diagonally).

It is not mandatory to move an entire phalanx. If the player has, for example, a line of five pieces, he can move only the first three (i.e., move a phalanx of dimension three).

The phalanges move in one of the two directions of the line that defines them (for example, a horizontal phalanx can move to the left or to the right).

The victory condition is checked before the player makes his move. If, after the move, a player has more pieces on his last row than his opponent, the latter still has an opportunity to rebalance the board position (either by capturing pieces on his first row or by placing pieces on his last row).

An example of a phalanx movement: From the starting position, White moved the phalanx defined diagonally by the pieces f1–g2 one square, with the first piece of the phalanx at h3. This movement is described in the notation f1,g2–h3. Next, Black moved e12,f11–h9. Then, White continued with the horizontal phalanx from h1 to h3, moving it a maximum of 3 squares, that is, h1,h3–h6. The result of these three moves can be seen in the following diagram.

The pieces always move forward, to an empty square, either on their column or on one of their diagonals. The diagram on the left shows where each piece could move if it were their turn to play.

In the following diagram we have an example of a phalanx capture. The black phalanx h12,h9, with four pieces, moves three squares down until it encounters the first piece of the white phalanx, of size three. Since the white phalanx is smaller, it is captured and removed from the board. If the white phalanx were equal to or larger than the black phalanx, this move could not have been made.

The following diagram shows a position where White has the advantage. White's horizontal phalanx on row 1 consists of seven pieces and can withstand attacks from Black's two potential phalanxes (e5, c3 and e5, e3). Black's horizontal phalanx on row 12, with six pieces, cannot prevent attacks from White's two vertical phalanxes (a8, a9 and j5, j8) that are eight files apart. White begins the attack with j5, j8–j12, wearing down Black's horizontal phalanx with successive captures. When this attack is over, the phalanx on row 12 the can advance without resistance to house a12.

References

1. [GG] Sackson, S., A Gamut of Games, Random House, 1969.