H. G. Muller wrote on Sat, Feb 18, 2012 12:39 PM UTC:
Chess-variant should be a rather loosely- defined concept; trying to make a strict definition will always lead to unnatural inclusions or exclusions. The defining characteristics of 'greater Chess' are IMO:
1) Turn-based two-player game with complete information
2) Played by moving pieces between discrete positions ('board squares')
3) The players can move one piece per turn
4) Pieces capture by replacement
5) Many different piece types
6) One piece type is 'royal', the loss of which ends the game
7) One piece type is much more abundant than the others, quite weak, and moves irreversibly and can promote.
Violating one or more of these rules doesn't necessarilly immediately diqualify a game for being a Chess variant. But if you violate a rule very badly (e.g. win by total extinction, in stead of check-mate, as in Suicide Chess), you'd better follow the others to the letter, or you are in trouble. So Suicide is OK because it does everything exactly the same as FIDE Chess (which is a recognized Chess variant, so its tiny transgressions of rule [3] and [4] through e.p. capture and castling are forgiven) there is little doubt it is a Chess variant.
So things like Turnless Chess (badly violating [1]), Marseillaise Chess (badly violating [3]) are still well out of the danger zone. DarkChess and Kriegspiel (bad violation of [1]): OK. Ultima I am not so sure about. I am inclined to say 'no, too outlandish!' on that one. Although it does have a royal piece, which even moves like an orthodox King. But the 'Pawns' are not irreverible, capture is almost exclusively other than replacements. So that is two badly violated rules. And indeed the game does not 'feel' like Chess.
Chess-variant should be a rather loosely- defined concept; trying to make a strict definition will always lead to unnatural inclusions or exclusions. The defining characteristics of 'greater Chess' are IMO: 1) Turn-based two-player game with complete information 2) Played by moving pieces between discrete positions ('board squares') 3) The players can move one piece per turn 4) Pieces capture by replacement 5) Many different piece types 6) One piece type is 'royal', the loss of which ends the game 7) One piece type is much more abundant than the others, quite weak, and moves irreversibly and can promote. Violating one or more of these rules doesn't necessarilly immediately diqualify a game for being a Chess variant. But if you violate a rule very badly (e.g. win by total extinction, in stead of check-mate, as in Suicide Chess), you'd better follow the others to the letter, or you are in trouble. So Suicide is OK because it does everything exactly the same as FIDE Chess (which is a recognized Chess variant, so its tiny transgressions of rule [3] and [4] through e.p. capture and castling are forgiven) there is little doubt it is a Chess variant. So things like Turnless Chess (badly violating [1]), Marseillaise Chess (badly violating [3]) are still well out of the danger zone. DarkChess and Kriegspiel (bad violation of [1]): OK. Ultima I am not so sure about. I am inclined to say 'no, too outlandish!' on that one. Although it does have a royal piece, which even moves like an orthodox King. But the 'Pawns' are not irreverible, capture is almost exclusively other than replacements. So that is two badly violated rules. And indeed the game does not 'feel' like Chess.