Kaissa or "the game" is taken from passages of the books of Gor by John Norman. Kaissa is played differently throughout the books. The books provide much information about the game, though they do not provide a complete set of rules for playing the game. It is at this point that PortKar Industries filled in the blanks. The three variations found here are the only official PortKar endorsed versions under US copyright law. Each in there own way partially supported by the books.

Kaissa though similar to chess, is played with more pieces on a larger board. There are ten different playing pieces, with twenty one or twenty two pieces per side depending on the variation played. Pieces represent warriors of cities at war, each attempting to capture the other's Home stone. There are two sides Yellow and Red, Yellow plays first. The Home stone is the most important piece it represents the heart of your city. It is what you must protect and it is your opponent's Home stone you must capture.

Kaissa is the eastern European spelling of Caissa the goddess (muse) of chess. Taken from a poem by Sir William Jones in 1763. Based on Vida's 'Scacchia ludus', in which the nymph is referred to as 'Scacchis'. Mars asks the god of sport to invent a game that will soften the nymphs heart.

"A lovely Dryad ranged the Thracian wild, Her air enchanting, and her aspect mild. To chase the bounding hart was all her joy, Adverse from Hymen and the Cyprian boy. O'er hills and valleys was her beauty famed, And fair Caissa was the damsel named".

**Kaissa was also the name of the first Russian chess computer.