Something like Mao, but for chess!
Players begin with just their kings in the usual starting postitions, may take a turn to declare rules on the future play of game as in Mao, may take a turn to bring a piece into the game, or may take a turn to move a piece. If a piece has not been introduced to the game before, such as a bishop being played on the first turn and given an ability, all other pieces of its kind will have the same ability. A piece cannot have an ability declared for it once it is already in the game, and it may not move the same turn an ability is declared for it.
Basics
It contains some rules that cause impurities in the core idea of Mao, but this is a necessary part of a different medium. Hopefully, these changes will make it have a easier character, more based on adapting to new situations rather than fumbling in the dark, as you try to figure out your friend's favorite, most fiendish rules.
You'll want to read both Mao and How to play Mao first.
To quote Apoxy Butt, the only rule I can tell you is this one.
Well, that's not true at all, to be honest. You'll have to endure my sacrilege, and in general, you're allowed to discuss the rules and their effects, at least until I feel better about how the game works. My current intent is to create a dynamic game environment, instead of a game of figuring out what the rules are. This may change.
So, the rules.
I'll go over those, then give a sample game.
Two variants, rules must be declared or rules are not declared, are possible. I am not sure how the game may work with no declarations.
All rule declaring must follow the Mao rules.
Ground rules of the game
Both sides get one king, placed at a4 and h5. The object of the game is to checkmate the opposing king.
Both sides declare two rules for the game. These rules affect one of the variables that exist in the rules following. Each declaration is considered a turn.
Constants of pieces
A piece will be moved in the way it does in Chess.
Pieces may not be declared static or temporally or permanently rendered immobile.
Degrees
Where rules imply a variable, the threshold will be one, or half where one cannot be applicable.
Any rule that implies a variable may be incremented by one per turn spent doing so.
Introducing pieces into the game
Each turn, a player may choose to declare a piece, stating any ability it might have. Where it is set determines whether it moves on points or squares.
A piece may have (two or one) actions specific to itself. A ability will affect all pieces equally, and where a piece has rules originating in Chess, those will supercede the newly made rule.
Behavior of Pieces
An ability will count as any action that is above and beyond the traditional rules of chess.
An ability may be placed in one of four categories. An ability may be passive, and always and equally effective upon pieces of both sides. An ability may be activated instead of capturing a piece the moving piece may capture. In this case, the ability must where the moving piece will end its turn, given that it may not occupy an occupied location. An ability may be an incremental enhancement of the actions it may already take. An ability may be performable instead of moving, influencing those square it can ordinarily move to.
An ability may only take effect once a turn.
An ability may not render an piece immune to capture.
An ability must affect another piece, and may performed instead of moving, or instead of capturing a piece. An ability may performed at the end of a move.
An ability is not able to capture another piece.
A piece has potential influence in both movement and abilities on the points or squares around it. A piece has potential influence on the points or squares that directly surround it. So, each point is surrounded by 4 squares, and a square by 4 points.
Pieces may not share a square and it's corners, nor a point and the squares that define it.
A piece may capture an opposing piece if it ends its movement in a square or point that is occupied or directly adjacent to that opposing piece. The capturing piece will stay in the point or square it ended its movement on.
Only one action may be performed a turn. A move is considered to be the movement and action, where the action is the act of either landing on an empty square, capturing a piece, or activating an ability.
When moving, a piece (may choose to affect and be affected, must affect and be affected by, or will not affect and be affected by it's opposing location). This is the potential influence.
Each turn, a player may choose to place a piece that is already declared in the (quarter or half) of the board that the king is currently in. This piece may be immediately used.
Where declaring if a piece is under the reach of a piece's action, a piece is considered within range if it's points and squares are in line with the points or squares of any other piece's abilities.
A piece may not move to its own location, to act on pieces potentially within its zone of control.
Pieces may declared only as many times as the pieces exist in Chess.
A piece will move as it does in Chess.
The first part of a game
White goes first and makes poor decisions, Black goes second and makes good decisions.
White declares that any piece may move in half the directions one space. This half of the directions is the rank and file.
Black declares that a piece may choose to effect and be effected by pieces in the opposing movement space.
White places a rook on the point f-g, 5-6. He declares that it prevents all movement within the points of the squares it touches, without making itself vulnerable. In other words, it extends the range for which a rook blocks space by one, but not the range in which it is vulnerable. It's range variable is one.
Black places a pawn at d8. He declares that it may move two spaces to its forward diagonals instead of one. This is an increment of the pawn's ability to attack on the forward diagonal to the square next to it.
White places a pawn at h6.
Black places a bishop at d2 and declares that it may ignore a single piece's occupancy in a square, moving instead to a square past the blocking piece.
White places a bishop on g7.
Black places a knight on d7 and declares that if it may move onto a square containing a blocking piece, it may take another jump to move or capture where it may reach from the piece it used as a trampoline. This ability places the king in check, as it may be used on black's next turn to bounce off the white rook.
Now, let's resolve these rules without adding more to the board (in a real game, this phase of piece declaring would likely last much longer)
White moves his king to f8. The king is no longer in check.
Black moves his pawn to f6, capturing the rook. This places the white king in check from the black bishop, as the rook is no longer using its added ability to prevent movement immediately around it.
White moves his king to g6. The king is no longer in check.
Black moves his knight to f6, using the black pawn as a jumping point, to capture the bishop at g4. White begins a most unkind description of Black's sexual preferences.
I'm not sure where to go from there, I'm still thinking about how it works, I need more people to play test it with besides myself. Play test it, or try fixing it a bit. Let me know if it works at all or not, and what doesn't work in it.
Alternately, let me know if this doesn't make a lick of sense.