Definitions
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
