Switch-side chain-chess

We explain the details and implications of a new chess variant that is more challenging for humans than the standard version of the game. A new rule states that either player has the right to switch sides if a `chain´ or link of pieces is created on the board. This appears to increase significantly the complexity of chess, as perceived by the players, but not the actual size of its game tree. `Search´ therefore is less of an issue in computational approaches to playing it. The advantage of this variant is that it allows research into board games to focus on the `higher level´ aspects of intelligence by building upon the approaches used in existing, `mature´ chess engines. We argue that this new variant can therefore more easily contribute to gaming intelligence than other games of high complexity such as Go and Arimaa.