FRENZY

Copyright (c) 2002 Cameron Browne

This game is played on the following 8x8 square board:


SCHOOL - A group of connected fishes (the white stones). Adjacency is orthogonal and diagonal.
FISH - Moves to an adjacent empty cell or jumps over an adjacent fish if the cell on the far side is empty (like a hop in Chinese Checkers). A fish may jump any number times in a given turn, possibly changing direction, as long as no fish is jumped over twice.
All fish must remain in a single connected school. Any fish that stray from the school at the end of White's turn die and are removed from the board. If several groups exist, the largest group survives to become the new school. If more than one maximal group exists, Black chooses which group survives.
Spawning - At the end of White's turn, a new fish is added to any empty cell surrounded by eight occupied cells (fish or shark).
SHARK - A shark (the black stones) can move to any adjacent cell occupied by a fish, where it captures (eats) the fish. Any shark with no adjacent fish is immobilized until a fish moves next to it.
FIRST TURN - Black starts by playing the two sharks on occupied cells to capture (eat) one fish each. Capture is by replacement and eaten fish are removed from the board.
TURNS - At each turn, each player must move one of his stones.
GOAL - The White player wins if both sharks are immobilized. Black player wins if all fishes were captured.
 
An example

Black's turn. The shark at g7 is immobilized. Black moves d3 to c3 (the marked white fish). Doing so, the school splits into two groups of equal size (4 fishes each). Black may choose what group is captured.

Black must choose the south group, because if not, White then would move c2-c1 thus winning the game.

The original rules of FRENZY does not work. The Sharks don't have a chance to win. One way to solve this problem is to give symmetry to both players, each one has a school of fishes and a pair of sharks (this can easily be extended to 3+ player games):

2-FRENZY Rules (board is split by 32 fishes on each half of the 8x8 board, before the game starts, both players place their sharks on top of opponent fishes capturing them).

Each turn a player makes two moves, with different animals.
Each move is either a fish move as in Chinese Checkers; or a shark move as a chess king capturing a foreign animal.
If after any turn a shark is isolated from all foreign animals, it immediately dies of isolation.
If both a player's sharks are dead or his fishes are all captured, he loses; if this happens to both players simultaneously, it is a tie.
If a player's school of fish splits into two or more isolated schools, all but the largest die. If there are equal largest, the player who made the move decides which.