- neither your king nor castling rook have moved
- there are no pieces between your king and castling rook
- your king does not pass through check on the way to its final square
- your king is not currently in check
- there is space for your king and castling rook to land in their final castled positions - for kingside castle: that is F1 (rook) and G1 (king) for white and F8 (rook) and G8 (king) for black, and for queenside castle: that is C1 (king) and D1 (rook) for white and C8 (king) and D8 (rook) for black.
960 castling
The exact starting squares of king and rook do not matter. The destination squares (on which king and rook are on after castling) are always as indicated as ceefor, also in chess960.
Castling in chess 960 is really starting to confuse me, can anybody shed me some light on this please