Applied Concepts released a chess computer which is now considered amongst the very rarest, the Boris Handroid. I have seen it said that this was a prototype never released for sale, but there are priced retail advertisements from Germany suggesting that it could have been available there, and the distinction is a fine one anyway. The associated German marketing company Sandy Electronics also sold the very rare La Regence, but this was not made by Applied Concepts.

The Boris Master, with the built in rechargeable battery, is seen far less frequently than the standard Boris. The Destiny Mini Master is harder to find than the near identical Destiny Progidy. On the rare list could also be added the 3.0, 3.5 and 4.0 program modules for the Auto Response Board, the first auto sensory board to reach the market. There are also some modules for the Modular Game System and Great Game Machine which are hard to find, particularly the Gruenfeld S (openings) and Capablanca S (endings) modules and the Steinitz program module is also fairly rare.

For the Rare section of the website I have chosen these :-

(1) Destiny Mini Master
(2) Great Game Machine with Steinitz program module and carry case
(3) Auto Response Board (ARB) with 4.0 50S module with the leather carry bag