I've set up an online implementation of the board game Entropy [Hyle 7] by Eric Solomon. I'd like to get some people test it out, before I post anything substantial here. If you're interested in doing turn based Entropy, drop me a PM.
"He draws them out unseen one at at a time and places them on any empty square."
Is it merely the draw that is unseen or does Chaos have to choose the empty square before knowing what color he has drawn? I would guess it's the former.
I've chosen to interpret it as the former, since that is the way Eric Solomon's implementation seems to work: http://www.ericsolomon.co.uk/en/entropy.html. They are randomly selected, but you can see them before you place them.