From the publisher:
Kerak is a two-player, abstract strategy board game. Players take turns moving their pieces across the 62 space hexagonal board, with the goal of capturing their opponent’s castle.
Each player controls 18 pieces: 9 infantry, 3 archers, 2 cavalry, 2 knights, 1 hero, and 1 castle. Pieces are distinguished by their movement and strength values. Pieces also support each other, meaning that attacking and defending pieces are “strengthened” by those around them.
Therefore, Kerak plays in two strategic dimensions: that of individual pieces, and larger strategic groupings.
Also, since players set up their pieces one at a time, in any order or configuration, no two games of Kerak start the same. Every game starts and ends uniquely.