On 13/11/2020 20:01, Andy Latto wrote:
If we take the actual chess rules, where having no legal moves is a stalemate draw, then I think that prohibiting a move that leads to a forced capture of the king in two moves (or equivalently, allows a mate in 1) leads to a game that is an easy draw for minimally competent players. Here's the simple drawing strategy. If all moves lead to mate in 1, the game is a stalemate draw, by the new rule. If there is at least one move that does *not* lead to a mate in 1, make any such move. This strategy cannot be defeated, so the game is a draw unless someone blunders by allowing a mate in 1 where a different move would avoid it.
I don't think that's quite the right generalization of the rules of ordinary chess. If you compare ordinary chess with "take-the-king chess", the right way to describe what changed is that if every (otherwise) legal move leads to immediate loss then you (1) lose if a null-move also leads to immediate loss, and (2) draw if not. So for the iterated version, the correct rule would be: if every (otherwise) legal move gives the opponent a mate in 1, then you (1) lose if a null-move also gives the opponent a checkmate, and (2) draw if not. I believe this version is neither exactly equivalent to ordinary chess, nor trivially a draw. (By a "null-move" I mean simply doing nothing, which of course is not actually a legal move in chess.) -- g