Advanced format ruling
Magical Thorn
Card effect (current official text)When your opponent's card(s) in their hand are discarded to the Graveyard, inflict 500 points of damage to their Life Points for each card that was discarded.
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.