Forum:Question about Trap cards

Hey guys I just have a quick question. If my opponent draws a card and is planning to attack that turn, can I play Threatening Roar right after they draw or do I have to wait for them to Summon a Monster, play a spell/trap or monster effect and chain my card to it?

71.255.50.32 (talk) 15:48, August 16, 2010 (UTC)