There's nothing wrong with a tactical game, of course, it's simply a matter of finding a slightly different recipe so that the mix of flavors is balanced differently.
In order to make it difficult for future chefs to devise new recipes, I here present a complete cookbook of new forms of Limited Doublemove Chess.
In order to make two moves in one turn, you must move two different pieces of the same type. For example, you can move two Knights, or you can move two different Pawns.
There is no penalty if you can only make one of your two moves.
You must make the second move of your turn if you can. This is actually the normal rule, but because zugzwang seems more likely in this game I thought I should emphasize it.
King and Queen count as the same type of piece.
You really should pick up one piece in each hand and move both at once, even the rules clearly show that one move is made before the other.
It's inconvenient that King and Queen are the same "type", isn't it? This might be a reason for underpromotion in problems...
In the endgame, the game may become identical to FIDE Chess. For example, "King plus Rook plus Pawn versus King plus Rook": no doublemoves are possible.
The rule that you must make two moves if you can will be inconvenient at times. This is deliberate.
Your second move must be an echo of your first. In other words, in order to make two moves in one turn, you must move two pieces of the same type, and move them in the same direction, and move them the same distance.
If one of the moves is a capture, the other must also be a capture.
The rule that you must make two moves if you can will be inconvenient at times. This is deliberate. This situation will arise more often in Echo Chess than in Two-Fisted Chess. Think of it as a new kind of Zugzwang.
1. Nc3 (HFD)c8-c5,(HFD)f8-f5Will White move his Knight and be mated by (HFD)f5-e4? Or will he allow 2...(HFD):c2,(HFD):f2 checkmate?
2. f4,e4 (HFD)c5-d4,(HFD)f5-g4 3. Qe2,Kf2 (HFD)d4:d2+,(HFD)g4:g2+ 4. Kg3,Qf3 (HFD)g2:f3,(HFD)d2:c3 5. ResignsBetter 2. f3,e3
For example, 1. e4 e5,d5 2. Nf3,Nc3 Qe7,Kd7 is a legal series of moves.
The basic doublemove rules apply except as follows:
You may not move the same piece twice in one turn, and in fact you must move two different kinds of piece to make a doublemove.
If one move is a capture, the other must not be. However, you are permitted to make two non-capturing moves even if a capture is available.
If one move advances, the other must not be. You are permitted to retreat with both moves, to go East with both moves, but you may not go forward with both. (This rule makes the biggest difference.)
The game has a certain interesting resemblance to Avalanche Chess.
Each turn, each player must make at least one move.
If you only make one move, you get credit for half a move.
Each turn, each player may make as many moves as he can afford.
Check must be respected, and your first move of a turn must get you out of check.
The very first turn of the game, White gets only enough gas for one move.
The primary strategic tension here is between saving and spending. If you save up enough gas to make ten moves in one turn, surely you can checkmate; but in the meantime, your opponent might be able to win by making a few extra moves here, a few there.
How embarassing it would be to get checkmated with 8 moves in the bank!
I think that the average game will be 20 moves or fewer.
A Pawn on the second rank still has its double-step, even if it moved and was undone; Castling is still legal even if it was previously attempted and undone.
There is no penalty for parts of your turn you cannot take.
If your opponent was only able to make one move, you may not undo it.
Note: you may undo a move even if it makes the opponent's other move illegal, and even if it makes your own move illegal. For example, after 1. d4,Bg5 Nc6,Nf6(d4-d2) the position looks like White played the illegal move 1.Bc1-g5; but it's okay!
Example: after 1. e4,Bc4 e5,Nf6(e4-e2) 2. Nf3,O-O(e5-e7) e5,Nc6(undo O-O) 3. O-O,Rf1-e1(e5-e7), Black cannot undo White's Castling; White's most recent turn could not undo Ng8-f6 because that move was not part of the most recent pair of moves; White was able to Castle and play Re1 becuase Castling is a King move.
The common idea was the two-part move: first you make an ordinary legal move, then if you're not checkmated you may do the second part which is something special and different for each game in the family. And of course Avalanche was first thought of as a new kind of Doublemove Chess.
Imaginary Doublemove Chess follows the same rule....
In Imaginary Doublemove Chess, both moves get made but one of the two moves usually gets cancelled.
In Imaginary Doublemove Chess, you can undo an enemy move even if it makes the other move illegal.