Joseph is correct about the Fortress. It is described incorrectly in the
readme file and therefore on the webpage. It's my error, not David's. It
captures ALL adjacent units, not just orthogonally adjacent ones, after
capturing a non-inert unit. Also, There's now a 9x9 version of the game
with only King plus four pieces per player -- a much easier way to get
into the game without having to learn a lot of rules.