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True, a special 'inherit directions from square' modifier (say '?' as 'a' is already taken) would allow a very elegant move description in Smess-like games. But that is really a very specific case. In Elk Chess the Elk moves as a Rook or as a Knight, depending on the color of the square it is on, and the square property would have to encode more than just a direction. A Querquisite moves as the piece that started in the rank it is in, so it can move like many different pieces. Gerd Degens has recently submitted many variants that have location-dependent moving: Avatar, (where there is only one type of piece next to the royal King, which can move like any orthodox Chess piece in a pattern that is scattered over the board), Bull's Eye (where pieces in the 4 central squares move as Amazon). He also had a variant (I forgot the name) where on some squares pieces keep the move of the square they came from. This is an awful lot like promotion, as on the same square a piece could now have different moves. So the move the pieces have on a square can no longer be a square property.

In Kyoto Shogi the piece type toggles on every move, with as a result that you often reach the same square in either of the two forms, or return to the same square flipped. So the move depends on history rather than on a square property. But the move change does not have the permanence we associate with promotion. A mapping (micro-type, square) -> new micro-type can still perfectly describe all the mentioned behaviors. In micro-Shogi the pieces only flip when they capture, so there a mapping (mover micro-type, destination square, occupant thereoff) -> new micro-type is needed. But that is a very poweful way of describing things. For a given square that mapping of (mover micro-type, destination occupant) -> new micro-type could be considered a (rather complex) 'property' of that square.

I don't think that 'conceptually' really means much. As far as I am concerned game rules are an abstract mathematical concept: a set of game states acting as nodes of a directed graph that indicate the legal transistions between one game state and another. Where the game states imply the player who is going to decide which of the legal transitions out of the state will be taken, and game states without any exits are labeled with a game result. Any verbal description that unambiguously defines this graph is as good as any other, and concepts like turn, piece, move, cell, type are not more than personal preferences of the person or machine learning the game, to help him remember and apply the rules. Often different concepts are just rewording the same thing. One could for instance call micro-type also 'current move set of the piece', and it might sound much less abstract to some.