Ssehc

Ssehc is a chess variant with normal-chess rules played in reverse.
Moves must be made such that if the game were recorded and played backward it would appear to be a legal forward chess game with an unusual starting position.
The goal is to end the game with your pieces in their normal-chess starting positions (or as close as possible).

Starting a Game

Setup the board with each king two squares forward from their normal starting position (white king on F3, black king on F6).
All other pieces are off the board (they start captured) and will be un-captured back onto the board throughout the game.
White starts the game by un-moving their king. Players alternate turns after that.
Each player’s turn has two phases: un-capture then un-move.

Un-Capture

This phase is optional and you may choose any one of your captured (off-board) piece to un-capture (unless noted in “help”).
Place your captured pieces onto the board at the location from which your opponent un-moved their piece.

Un-Move

This phase is required. Choose one of your pieces to un-move (unless in Un-Check, see “Help”).
Rooks, knights, bishops and Queens are simple (they un-move like they move in normal-chess). For kings and pawns, see “Help”.

End of Game

End: Once you have all your pieces on the board, if all squares in the first two rows of your board are occupied OR your only legal un-moves would take a piece out of its home position then instead of your un-move phase you may declare the game is over by announcing “good enough”.
Scoring: Players get one point for each piece in its normal-chess-start-position and loose two points for each piece in enemy territory (anywhere in the last two rows). The player with the most points wins.
Resigning, or draw by repetition/stalemate/agreement/50-move-rule are the same as normal-chess.

Help

King and Pawn rules are conditional and asymmetrical in normal-chess so they are complicated in reverse. They can add restrictions to which piece may un-move, where to, if the un-capture phase occurs and which pieces may be un-captured. These will be easier to remember and understand if you think of these as normal-chess rules (which you already know and love) played in reverse.

Kings (are Complicated in Reverse)

Un-Single-Step: A king may un-move one square in any direction (same as normal-chess).
Un-Castling: If your king & rook are in a castled position, and there are no pieces between them, and you’re not un-castling into, out of, or through check, then you may un-castle (un-move both the king and rook to their starting position).
After Un-Castling: Your opponent may not un-capture a piece on their next turn. You may not un-move your king or this rook for the rest of the game.
Check: You may end your turn with your king in check (and announce “check”) as long as it can legally be removed from check before your next un-move.
Un-Check: You may not end your turn with your opponent in check unless your opponent can legally remove themselves from check with an un-capture. A player who starts their turn in check must un-capture out of check.

Pawns (are Complicated in Reverse)

Un-Capture: Pawns may not be un-captured to the first or last row.
Un-Single-Step: A pawn may un-move one square toward its home row (but never to the first row). This prevents your opponent from un-capturing.
Un-Double-Step: A pawn on the 4th row may un-move two squares toward its 2nd row. This prevents your opponent from un-capturing.
Force-Un-Capture: Pawns can un-move one space backward and to a side (but never to the first row). This forces your opponent to un-capture a piece. This is only legal if your opponent can legally un-capture a pieces to this location.
Un-Promotion: Any non-king piece on your last row can be swapped with a captured pawn before you un-move it (the old piece becomes captured and is removed from the board). If the pawn can’t legally un-move from that square, un-promotion was not legal.
Un-En-passant: If your opponent’s pawn Force-Un-Captures from your 3rd row to your 4th row, you may un-capture a pawn on your 4th row on the file their pawn un-moved from (and announce “en-passant”). You must then un-double-step this pawn on your un-move phase and if you can’t legally do so, then un-en-passant wasn’t legal.

Consider taking a picture after each phase and reviewing them in reverse order after the game. This game was invented by Alex Hennings in 2018. It is posted here as an exercise in technical writing.