Deflection

Deflection is played on the same board, and with the same pieces, as Gothic Chess. The board is 10 columns wide by 8 rows deep, and the piece set includes all of the usual chess pieces plus two new pieces for each player, the marshall and the archbishop. (The opening setup is shown in Figure 1.) In addition to the Gothic Chess pieces, Deflection makes use of six neutral pieces called, naturally enough, deflectors. The deflectors change the topology of the board, both enhancing and interfering with other pieces' powers of movement.

Figure 1. The opening setup in Deflection is identical to the setup in Gothic Chess. (The queen is separated from the king so that all of the pawns are protected in the opening position.)

 _ _ _ _ _ _ _ _ _ _
|r|n|b|q|m|k|a|b|n|r|
|p|p|p|p|p|p|p|p|p|p|
|_|_|_|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|_|_|_|
|P|P|P|P|P|P|P|P|P|P|
|R|N|B|Q|M|K|A|B|N|R|

The marshall (called a chancellor by the Gothic Chess folks) can move like either a rook or a knight. The archbishop can move like either a bishop or a knight. All of the usual rules of chess apply in Deflection, with only one minor change, which is made necessary by the added width of the board: In castling, the king always moves three squares toward the rook.

Why use Gothic Chess as a basis for Deflection, rather than ordinary chess? First, because a variant that adds a few neutral pieces seems to benefit from having a few extra squares. Second, because the deflectors only affect pieces that make multi-square moves in a straight line, so it seemed useful to have a couple of extra pieces of that type on each side.

The Deflectors

At the beginning of the game, each player has three deflectors. They are "in hand," and are placed on the board during the course of the game. Deflectors are of three types -- 45-degree, 90-degree, and 135-degree. Each player begins the game with one of each type. In game diagrams and game records, the three types can be notated with the abbreviations J (for the 45), L (90), and V (135). Those letters are as close as you can get with ASCII characters to a graphic representation of the angles involved. In over-the-board play, poker chips -- white, blue, and red respectively -- can be used as deflectors.

Once placed on the board, a deflector deflects the path of any piece that passes over its square. Deflectors affect only pieces making multi-square straight-line moves. They have no effect on the king, nor on pawns (not even during the pawns' initial double-square move), on knights, or on the marshall and archbishop when the latter are making knight-type moves.

A deflector sits on a square like an ordinary piece, but it doesn't "occupy" the square. A piece belonging to either player can land on a square where a deflector sits. Deflectors have no effect on the movement of pieces onto or off of the deflector square; they affect only pieces passing across and continuing beyond an unoccupied square where a deflector is located.

Whenever a piece crosses the square of a 45-degree (J) deflector, its movement trajectory is deflected at a 45-degree angle. The 90-degree and 135-degree reflectors have similar effects. If you like, you can think of the effect as analogous to how light is bent by a prism, or how a miniature golf ball rolls up a mound and then rolls off in a new direction. The deflection is not optional; it is required whenever a piece passes over a deflector. Note that by using a 45-degree or 135-degree reflector, a bishop can change from white to black squares or vice-versa.

A piece can use more than one deflector in the course of a single move. It can even use the same deflector more than once, if other deflectors are positioned so as to allow it.

Perhaps the best way to explain deflection is with a few diagrams.

Figure 2. The queen, starting on b1, can reach the 45 (J) deflector on d3 using her normal diagonal movement. At this point, her trajectory is deflected by 45 degrees either to the left or the right. With the aid of the deflector, she can reach any of the squares marked with dots (in addition to the other squares she can reach without the deflector). She can no longer reach e4, f5, etc., marked 'x' here, because the deflector changes the direction of her travel.

 _ _ _ _ _ _ _ _ _ _
|_|_|_|.|_|_|_|_|x|_|8
|_|_|_|.|_|_|_|x|_|_|7
|_|_|_|.|_|_|x|_|_|_|6
|_|_|_|.|_|x|_|_|_|_|5
|_|_|_|.|x|_|_|_|_|_|4
|_|_|_|J|.|.|.|.|.|.|3
|_|_|.|_|_|_|_|_|_|_|2
|_|Q|_|_|_|_|_|_|_|_|1
 a b c d e f g h i j

Figure 3. The rook can take advantage of the 135 deflector to "bounce back" along a diagonal trajectory to either the left or the right. On reaching the 45 deflector at h3, its path is deflected again, allowing it to reach the squares marked with dots.

 _ _ _ _ _ _ _ _ _ _
|_|_|_|_|_|_|_|_|_|_|8
|_|_|_|V|_|_|_|_|_|_|7
|_|_|.|.|.|_|_|_|_|_|6
|_|.|_|.|_|.|_|_|_|_|5
|.|_|_|R|_|_|.|_|_|_|4
|_|_|_|_|_|_|_|J|.|.|3
|_|_|_|_|_|_|_|.|_|_|2
|_|_|_|_|_|_|_|.|_|_|1
 a b c d e f g h i j

Figure 4. The white bishop (h6) is checking the black king (f5) using two deflectors. The 90-degree deflector sends the bishop upward to d4 and c5, where the 135-degree deflector sends it back to the right. The bishop is not, however, able to check the king by means of the h3 deflector, because the bishop's move always begins on a diagonal.

 _ _ _ _ _ _ _ _ _ _
|_|_|_|_|_|_|_|_|_|_|8
|_|_|_|_|_|_|_|_|_|_|7
|_|_|_|_|_|_|_|B|_|_|6
|_|_|V|.|.|k|.|_|_|_|5
|_|_|_|.|_|.|_|_|_|_|4
|_|_|_|_|L|_|_|V|_|_|3
|_|_|_|_|_|_|_|_|_|_|2
|_|_|_|_|_|_|_|_|_|_|1
 a b c d e f g h i j

Figure 5. Here, the rook on i3 can reach g8 (marked 'x') by using the i6 135 deflector twice. The rook travels up the i file, deflects down to the 90 deflector on g4, deflects upward again to the 135 on e6, bounces back to the right, and hits the first deflector again, this time from an approach angle that allows it to reach g8. Technically, once the rook has entered the i6/g4/e6 triangle, it could loop forever, preventing the game from continuing. This is not allowed.

 _ _ _ _ _ _ _ _ _ _
|_|_|_|_|_|_|x|_|_|_|8
|_|_|_|_|_|_|_|_|_|_|7
|_|_|_|_|V|_|_|_|V|_|6
|_|_|_|_|_|_|_|_|_|_|5
|_|_|_|_|_|_|L|_|_|_|4
|_|_|_|_|_|_|_|_|R|_|3
|_|_|_|_|_|_|_|_|_|_|2
|_|_|_|_|_|_|_|_|_|_|1
 a b c d e f g h i j

Placing & Moving the Deflectors

As indicated earlier, each player begins the game with one of each type of deflector in hand. After moving a piece, but before the opponent moves, a player may place a deflector that is "in hand" on any vacant square on the board. A deflector may not be placed on a square already occupied by another deflector. Placing a deflector after any given move is optional; it is not required.

Once placed on the board, a deflector cannot be picked up again. It stays on the board for the rest of the game.

After all three of a player's deflectors have been placed on the board (but not before), the player may move deflectors that are already on the board. The deflector move is made after the player's move and before the opponent's move, and again it is optional. Either player may move any deflector.

Deflectors move like rooks. A deflector's move must start and end on vacant squares. A deflector's move is affected by any other deflectors in its path. A deflector may not end its move on the same square as another deflector.

Ko Rule: Neither player may move a deflector back to the position it occupied immediately before the opponent's most recent move. At least one move must intervene before the deflector is moved back to its previous position. It is legal, however, to immediately move the other deflector of the same type onto the square just vacated.

Deflectors can never be captured during the course of the game, nor can they capture other pieces.

In case you're wondering why pawns can't use deflectors on their initial move, it's to short-circuit this opening. White moves the f2 pawn to f4, and then immediately places a 135-degree reflector on f6:

 _ _ _ _ _ _ _ _ _ _
|r|n|b|q|m|k|a|b|n|r|8
|p|p|p|p|p|p|p|p|p|p|7
|_|_|_|_|_|V|_|_|_|_|6
|_|_|_|_|_|_|_|_|_|_|5
|_|_|_|_|_|P|_|_|_|_|4
|_|_|_|_|_|_|_|_|_|_|3
|P|P|P|P|P|_|P|P|P|P|2
|R|N|B|Q|M|K|A|B|N|R|1
 a b c d e f g h i j

If pawns used deflectors, Black's king pawn could no longer reach f5 in a single move, which would give white an unacceptable advantage.