Definitions

In these rules, "adjacent" always means "orthogonally adjacent".

A bit is one of the two small one-colored square prisms that make up a piece.

A stack is a set of one or more bits piled onto each other on the same square. The color of a stack is the color of its topmost bit, which denotes its owner.

The height of a stack is the number of bits in it.

A group is a stack along with all other stacks one could reach from it through a series of steps between adjacent like-colored stacks. Thus, all stacks in a group are the same color.

The size of a group is the number of stacks in it.

Play

Black plays first, then turns alternate. On your turn, if possible, place a piece on the board so that it exactly covers two empty squares or two stacks that rise to the same height, without causing any bit to lie directly on a like-colored bit. At all times, at least one bit of every piece on the board must remain uncovered.

If you have no moves available, you must pass. Passing is otherwise not allowed.

The game ends when both players pass in succession. The player with the higher score in the final position wins. Your score is the biggest group size in which you have the greater number of groups. If there is no such size, your score is zero. If both players are tied at zero points, whoever made the last move loses.

Pie rule

The pie rule is used in order to make the game fair. This means White will have the option, on their first turn only, to swap sides with their opponent instead of making a regular move.

Notes

Wythe is based on TAIJI.

-description from designer