HexChad is the hexagonal variant of Chad, which was first published in The Gamer (May-June 1982).  In Chad the King is confined to his 3x3 castle and may move as either a King or Knight.  The Rooks can promote to Queens upon reaching the interior of the opponent's castle.  The attacker can only capture if he's on a castle wall capturing inward, the defender inside the castle can only capture an opponent on the wall.  Other than that, they just block each other.

HexChad is just one of the games invented by Christian Freeling; they can all be seen, and some of them played, on the internet in the MindSports ArenA.