The Chess Variant Pages

Potential Chess

All pieces start out with the potential to be any piece. After a piece moves, its potential must be reduced (if necessary) according to the specific move it has made.

Rules

At the end of the game, it should be possible to actualize all remaining pieces, and then, determining the starting array with the actual pieces, re-play the game as a orthodox chess game (albeit from a non-standard starting array).

Notation


coord1-coord2>piece1

   piece at coord1 moves to coord2 and is reduced to piece1

coord1:coord2>piece1(piece2)

   piece at coord1 captures piece at coord2 and is reduced to piece1. 
   captured piece is actualized into (piece2)


X   = any piece (ie. KQBRNP)
!K  = any piece except King (ie. QBRNP)
ABC = Potential to be an "A", "B" or "C"
!AB = Potential to be any piece except an "A" or "B"

Initial Array

   +---+---+---+---+---+---+---+---+
 8 | x | x | x | x | x | x | x | x |
   +---+---+---+---+---+---+---+---+
 7 | x | x | x | x | x | x | x | x |
   +---+---+---+---+---+---+---+---+
 6 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 5 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 4 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 3 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 2 | X | X | X | X | X | X | X | X |
   +---+---+---+---+---+---+---+---+
 1 | X | X | X | X | X | X | X | X |
   +---+---+---+---+---+---+---+---+
     a   b   c   d   e   f   g   h

Example moves

Array after turn 1:
1. d2-d4>QRP     a7-b5>n

   +---+---+---+---+---+---+---+---+
 8 |!k | x | x | x | x | x | x | x |
   +---+---+---+---+---+---+---+---+
 7 |   |!k |!k |!k |!k |!k |!k |!k |
   +---+---+---+---+---+---+---+---+
 6 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 5 |   | n |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 4 |   |   |   |QRP|   |   |   |   |
   +---+---+---+---+---+---+---+---+
 3 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 2 |!K |!K |!K |   |!K |!K |!K |!K |
   +---+---+---+---+---+---+---+---+
 1 | X | X | X | X | X | X | X | X |
   +---+---+---+---+---+---+---+---+
     a   b   c   d   e   f   g   h

After

1. d2-d4>QRP
white reduces all second rank pieces to not-kings because all these pieces were left in check at the end of white's move. After
1. ... a7-b5>n
all second rank black pieces are reduced to not-kings because they were left in check. Black's piece at a8 is also reduced for the same reason.

2. d1-d2>!bn     h7-g5>n

   +---+---+---+---+---+---+---+---+
 8 |!kn|!n |!n |!n |!n |!n |!n |!kn|
   +---+---+---+---+---+---+---+---+
 7 |   |!kn|!kn|!kn|!kn|!kn|!kn|   |
   +---+---+---+---+---+---+---+---+
 6 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 5 |   | n |   |   |   |   | n |   |
   +---+---+---+---+---+---+---+---+
 4 |   |   |   |QRP|   |   |   |   |
   +---+---+---+---+---+---+---+---+
 3 |   |   |   |   |   |   |   |   |
   +---+---+---+---+---+---+---+---+
 2 |!K |!K |!K |!bn|!K |!K |!K |!K |
   +---+---+---+---+---+---+---+---+
 1 | X | X | X |   | X | X | X | X |
   +---+---+---+---+---+---+---+---+
     a   b   c   d   e   f   g   h

After

d1-d2>!bn
white reduces the piece to a non-bishop, non-knight because of the way the piece moved (moved as a king, queen, rook or pawn). After
1. ... h7-g5>n
all black's potential pieces are reduced so that they cannot be Knights. This is because black now has two Knights and it is not legal to start out with more than two Knights.
Written by David Howe.
WWW page created: September 18, 1999.