Mutabor
Some 15 years ago, when I was still studying physics
in
Tuebingen,
my friend
Klaus-Peter Zauner
showed me the game
Mutabor
invented by
Karsten W. Theis.
I got totally hooked. Karsten captured the spirit
of Meta Chess, mentioned in the book
Goedel, Escher, Bach
by Douglas Hofstadter
in a much simpler game. It is very intriguing to play a game where the rules change all the time. Feels like a Lisp REPL.

