Bug

Bug, winner of the 2017 best combinatorial game award, is a 2 player combinatorial game where you build shapes on a hexagonal board, which then eat each other. The shapes that survive grow into different, larger shapes until one player runs out of space to grow (and thus wins).

The game is played with white and black stones on any hexagonal tiling. The author strongly recommends playing at first on a "hexhex3" board, and playing on larger boards only after accruing some skill.

The game originated in the author's thinking about a cognitive phenomenon called "perceptual binding", and how it may be used to make combinatorial games more easily understandable to the human mind, given its peculiarities.

Summary:

A bug is an entire group of connected, same-color stones on the board. A single stone is also a bug.

The size of a bug is the number of stones it contains.

The board starts empty. Black begins the game by placing one black stone on any empty space. Then, starting with White, the players take turns. Each turn has 3 steps, taken in order: 1) Grow, 2) Eat, 3) Bonus Grow

1. Grow: Place a stone on an empty space to either start a new bug or grow one of your preexisting bugs by one stone. You may not merge bugs, and you may not grow a bug to be larger than the largest bug on the board (regardless of color) prior to placement.

2. Eat: All your bugs which are adjacent to one or more enemy bugs of the same shape (possibly rotated and reflected) must eat (capture) those enemy bugs.

3. Bonus Grow: Increase the size of each of your bugs that ate, by exactly 1, by placing a stone of your color on any empty space adjacent to each such bug.

If eating would unavoidably force a bug to grow by more than 1 through a merger with another bug of the same color, no eating occurs.

If, after growing, a bug is adjacent to an identically-shaped enemy bug, it must eat the enemy bug (and grow again) if possible, and so on.

The first player who CANNOT place a stone in the placement step WINS.