- Circe: When a capture is made, the captured unit is replaced on its rebirth square if it is empty, otherwise, the captured unit vanishes. The rebirth square is a starting square for a piece of that kind (2nd rank for pawns, 1st rank for officers). A pawn remains on the same file when reborn, a non-queen officer remains on a square of the same colour.
Checks and checkmates are normal, but do pay attention that a capture response to a check may be illegal if the captured piece would still be delivering check after rebirth.
There are many other types of Circe, all grouped generally under the term Circe, even if they do not correspond to the details of the vanilla form.
- Anticirce (or Anti-Circe): When a capture is made, the capturing unit (including King) must come back to its rebirth square (according to the "modalités Circé"): if this square is occupied, the capture is forbidden. A Pawn capturing on its promotion rank promotes before it is reborn. Unless otherwise stated, captures on the rebirth square are forbidden.
- Circe parrain: The single move following a capture, the captured unit (except a King) accomplish, from its capture square, an exact copy of that next move. If the arrival square is occupied or if the journey bring it out of the board, the captured unit vanishes.
- Mars Circe: To capture, any unit return at first on its rebirth square (according to the "modalités Circé") which must be unoccupied, and then make the capture from this square.
- Anti-Mars Circe
- Circé Couscous: When a capture is made, the captured unit (except a King) is replaced on the capturing unit rebirth square (according to the "modalités Circé") if it is empty : otherwise, the captured unit vanishes. Unless otherwise stated, when a promotion by capture occurs, the rebirth square is the Pawn one.
- Circé Coucou: Like Circé couscous, but the capture of a Pawn is forbidden if it must promote and if one of the possible promotions is a self-check.
- Diagram Circe: Like Circe, but the diagram square of a piece is used as its rebirth square.
- Circé équipollent: When a capture is made, the captured unit (except a King) is replaced its rebirth square (the symmetrical square of the departure square in relation to the arrival square) if it is empty : otherwise, the captured unit vanishes.
- Mirror Circe: Captures are as in Circe, but the captured unit is reborn as if it were of the opposite colour.
- Vertical Mirror Circe
- Horizontal Mirror Circe
- Interchange Circe: captures are as in Circe, but the captured unit is reborn on the depature square of the capturing unit.
- Atomic Circe
- Antipodean Circe: For each captured piece a new piece of the same kind appears on the square 4 rows and 4 columns away from the square on which the capture took plade as long as this square is empty. If the corresponding square is occupied, the captured piece vanishes.
- Volcanic Circe: Like Circe, but a capture piece does not disappear if its rebirth square is occupied. In such a case, the captured piece is reborn "below" the occupying piece (without having any power at that moment). If the occupier moves, the captured piece reappears and re-gains its full power.
- Kamikaze Circe: like Circe, but the capturing piece is reborn as well.
- Symmetrical Circe: like Circe, but the rebirth-square is the square diametrically opposite the capture-square, with respect to the central point of the board (e.g. capture on g6, rebirth on b3).
- File Circe: a captured unit is reborn on the file of the capture rather than on its normal game-array square.
- Rank Circe
- Circe clone: A captured unit changes into a piece of the same kind as the capturing unit (without changing color) and is then reborn on the game-array square of the new piece, according to normal Circe rules. When a promotion by capture occurs, the captured unit does not changes into the promoted piece but into a Pawn and is then reborn in the same way it would be reborn after any other Pawn capture. In case the capturing unit is a King, normal Circe applies.
- Circe Cage:
1. Captured pieces are reborn if there is one or more rebirth squares for the captured piece. When there are none, the captured piece is definitively removed from the board. As kings can not be captured, checks and mates are orthodox.
2. Rebirth squares are called cages. A cage for a given piece is a square such that if the given piece occupied that square, its only legal moves would be captures.
3. When there is more than one cage, the side making the capture chooses the rebirth square from the available cages.
4. Cages are determined after the capture has taken place.
5. Pawns may rebirth on the first row, from which they can move like ordinary pawns, including making a double step from the second row.
6. Pawns may also rebirth as promoted pieces on the last row. In such case, the rebirth square must be a cage for the promoted piece, the type of which is chosen by the side making the capture.
7. A reborn piece is “brand new”; its move history is lost. For example, a white rook reborn on h1 retrieves the ability to castle
8. If a capture is also a check, then the range of legal rebirth squares can be very large, as any legal move must answer the check.
- Andernach Circe
- Contact Circe
- Turncoat Circe
- Circe Double Agents
- Alsatian Circe: Every diagram must be legal in orthodox chess.
- Chameleon Circe
- Diametral Circe
- Bedrich's Circe
- Promotion Circe
- Hydra Circe: When a piece is captured, it's reborn on its normal Circe rebirth square, and on the square that lies mirrored in the vertical line between the d- and e-file (e.g. a black pawn captured on c3 is reborn on both c7 and f7).
- Promotion Hydra Circe
- Parachuted Circe
- Equipollent-Chameleon Circe
- Jupiter Circe
- Super-Circe: When a capture is made, the captured unit (except a King) can be replaced on any empty square. A white Pawn reborn on the 1st rank , or a black Pawn on the 8th, cannot be moved.