what is the difference between ‘normal’ and ‘legacy’ castling?


Normal is dragging the king two square to the side you're castling on or click move to the destination square. Legacy also allows dragging the king to the rook to castle (this still works in 960 in Normal as well I believe)

Actually, dragging the king to the rook works in both. Legacy mode castling also works when clicking the king and then clicking the rook

Normal is dragging the king two square to the side you're castling on or click move to the destination square. Legacy also allows dragging the king to the rook to castle (this still works in 960 in Normal as well I believe)
thank you martin for this detailed response
On Chess.com, "legacy castling" refers to the previous rule implementation in which castling was permitted regardless of whether the king moved through or out of check. Castling is now allowed only if the king does not move through, into, or out of check, in accordance with the standard FIDE regulations. "Normal" should be used for rated games.