Advanced format ruling
Staunch Defender
Card effect (current official text)You can only activate this card when your opponent declares an attack. Select 1 face-up monster on your side of the field. During this turn, your opponent can only designate the selected monster as an attack target and your opponent must attack the selected monster with all face-up monsters.
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.