Advanced format ruling
Hedge Guard
Card effect (current official text)During damage calculation, in either player's turn, when a monster you control attacks or is attacked: You can send this card from your hand to the Graveyard; halve the ATK of that monster you control until the end of this turn, but that monster cannot be destroyed by this battle.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.