Advanced format ruling
Jam Defender
Card effect (current official text)When an opponent's monster declares an attack on a monster you control: You can target 1 "Revival Jam" you control; switch the attack target to that target.
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.