The chess variant Robber-Baron was created by Seth McGinnis in the summer of 1998 as an entry in Hans Bodlaender's 39 challenge.
+---+---+---+---+---+---+---+ | r | b | r | b | r | b | r | +---+---+---+---+---+---+---+ | |###| |###| |###| | +---+---+---+---+---+---+---+ | | | | | | | | +---+---+---+---+---+---+---+ |###| |###| |###| |###| +---+---+---+---+---+---+---+ | | | | | | | | +---+---+---+---+---+---+---+ | |###| |###| |###| | +---+---+---+---+---+---+---+ | R | B | R | B | R | B | R | +---+---+---+---+---+---+---+
Rogues and footpads are an individualistic lot, and won't stand for being mistaken for one another! (And, more importantly, one of them is the Baron.) Each player's pieces should be distinguishable and therefore numbered, or, better yet, named. If you are naming your robbers, you will get coolness points if you can stick to a theme, like: Robin Hood, Friar Tuck, Will Scarlet... or Fingers, Scarface, Bugsy, Mad Dog... or even Sleepy, Happy, Dopey, Sneezy, Grumpy, Bashful, and Doc.
At the beginning of the game, each player decides, in secret, which of his robbers is the Baron, and writes it down on a piece of paper. If a player's Baron is taken, he loses, and the other player gets to gloat because now he has all the gold. Note that because the opponent does not know which piece is the Baron (the King-equivalent), there is no equivalent to check or checkmate.
While Robber-Baron been by no means play-tested to exhaustion, I have played several games with my friend Neal, and we were quite entertained by the results. Not knowing which piece is the opponent's Baron can lead to some unexpected endings -- or lack thereof. Because naturally you want to keep your opponent from figuring out which piece is your Baron for as long as possible, one tactic is to treat it just like a normal piece, and to defend it only lightly. Obviously, this tactic can backfire, and halfway through the game you may find yourself surprising your opponent with the fact that actually, he has just won the game.
Another unexpected element is the strength of the board positions. It's easy to see that location is very important in this game; what's surprising is that whether a square is a powerful position or a dangerous position depends on whether the piece on it is moving laterally or diagonally. The changing move of the robber also causes the corners to be 'sticky': you can only move into a corner with a rook move, so the next move will be a bishop move. But since you must also make a rook move to leave, that means you'll have to spend an extra turn to flip the robber over to get it out of the corner.
And of course, we could also give the robbers different movements. A
Highwayman piece (alternating rook-knight) might be interesting, or we
might want to give the Baron the ability to move in knight fasion, if
the player were willing to expose the Baron's identity. It would also
definitely fit the spirit of the game to give pieces a "shooting"
attack, although I haven't decided yet how that would be best done.