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.