Halma's Spoiling Strategy Revisited
Saturday, 17th January 2015
Halma is an excellent game, much recommended for its simplicity of rules and depth of play. Like many more modern games, it has an almost magical ability to suit players of all abilities: there is depth, but you're not forced to think deeply in order to make progress and enjoy the game. It has one main flaw: a player who cannot win can prevent an opponent from doing so. The unsporting player simply leaves one or more of their pieces in their home yard, blocking their opponent indefinitely.
A long time ago I wrote a post about halma's spoiling strategy, with some proposals to avoid it. I rejected some of the more unsubtle ideas, like allowing pieces to move only forwards, or forcing the players to empty their home yards straight away, because these had a negative impact upon some legitimate strategies (like moving backwards to rescue a straggling piece, or build "ladders" from the very start, to help speed evacuation of the home yard).
My favourite was to amend halma's victory condition slightly, in a way that recognised that the winner's chances were being spoiled and to award them victory anyway. I liked it because it had no impact upon the rules of movement or the strategies of play. I included this suggestion in my recent book A Book of Historic Board Games.
But since then, I've thought of an alternative. This one does modify the rules of movement, but not in such a way that legitimate strategies are impacted. The two additional rules are as follows:
1. If a player has a piece remaining in his home yard, then only a forward move is allowed. This move does NOT have to be a piece still in the home yard.
2. For this purpose, a forward move is any move in which a piece ends up closer to the opponent's corner than it started. Thus a hopping move may include a backward hop, as long as the piece finishes further forward than it started.
This is easier to understand, I think, than the alternative victory condition I have already proposed (that if a player is blocked from moving forward by the opponent opposite, this is also a win). It is also more subtle than those solutions that insist a player must always move forward, or must vacate all pieces from the home yard as early as possible, in that the legitimate strategies are not impacted.
Since my regular opponents are all jolly good sports, I haven't had the opportunity to put this or any previous spoiling solutions to the test. But I thought I'd put the proposal out there for those who'd like to organise a tournament, or who otherwise need it.