Copyright (c) 2001 Mark Thompson
Jade is played on an empty hexagonal grid in the shape of a parallelogram with size MxN (both odd numbers and not equal). The size currently considered best is 11x9, but other sizes and shapes could be used. Since my diagram tool cannot draw this type of board, I present an example with size 9x9 (use your imagination to add two extra rows at one edge for a real game).
- TURN - On each turn, each player drops a white or black stone on an empty cell.
- One player is called Cross and the other is called Parallel. Cross starts the game.
- GOAL - Each player has a different goal:
- Cross wins if a group of either color is formed that connects all four edges
- Parallel wins if either pair of opposite edges is joined by "parallel" chains of both colors.
Cross just played the marked white stone and with this move, he wins the match.
If Parallel drops a white stone at cell , Cross will win using the white structure. If Parallel drops a black stone at cell , Cross will win using the black structure.
Jade can be played on Richard's PbM server. Some words from the author: Draws are impossible. Proof: Note that draws are impossible in conventional Hex, because when a board is filled either Black will connect the two Black edges or White the two White edges. So I claim that when a board is filled, either Parallel or Cross will have won a game of Jade. For if you color the edges as a Hex game, either Black or White will have won that Hex game; and if you then recolor the edges in the opposite colors, again either Black or White will have won this second Hex game. If the two Hex games are won by the same player, then Parallel has won the Jade game; if by different players, then Cross has won the Jade game. Q.E.D.