From the campaign:
Grid-Hammer is a board game for 2 to 4 players, 9-years and older, and is playable in as little as 30 minutes - or much longer when playing with more players or expansion sets. Grid-Hammer pieces move, climb, rotate, capture, transform, and combine into new hybrid pieces as they surge across the board, which we call the "Grid". Grid-Hammer is a game of capturing - similar to chess in that it has no random elements, but similar to American football, the object of the game is not simply to capture the opponent's most important piece, but instead to get past their defenses and cross their HOMELINE - that is, to exit with any one of your pieces off their side of the Grid- while preventing them from doing the same to you first. Play is action packed and strategic possibilities are infinite.
Although it can be described as a “pure strategy” game, Grid-Hammer plays like a “real-time” strategy game with an open game system that allows for many set up variations and play modes. Each expansion set introduces new levels of depth to the game so that even though there are no random events, there is an unfathomable variety of tactical maneuvers.