Hearthpwn

Opponent Mage's Explosive Runes doesn't trigger my Duplicate secret (they kill my minion but I don't get duplicate copies).

Maybe that's because Duplicate doesn't trigger on your turn?

Very fun with Molten Giant and Mountain Giant

Yes - in the same manner that a gold Mirror Entity with give you a gold copy of the opponents played minion.

For which section of naxx is this card unlocked? I want to use it with Reno

Duplicated Dr. Boom finally after dozens of matches and the first thing my opponent decided to do after the second Dr B was Holy Nova and take 13 damage to face and concede.

duplicate sludge belchers is always good :)

Quote from Pgbearensen >>

I think this is Grand Magus Telestra from the Nexus encounter in WoW.?

Yes it is! Nice catch.

Just played against this card. The mage was able to get 4 Bloodhoofs in their hand, for a total of 5 played. Card seems a bit too good, but that may be just because I got rocked by it.

A way to recycle creatures. This seems sweet with an argent commander kicking the bucket. I especially like him after a kirin tor mage, because of the mana efficiency and that a 4/3 for 3 was already better than expected.

Do note that you can play around him with certain classes. Be mindful of playing against mages and shamans that you don't end up with sheep and frogs.

I love this card. This is my new favorite mage secret

I have used this card in a freeze Mage variant with massive success, save it for molten giants, nothing is more fun than spitting out free giants, lock down zoo early with the new naxx taunts, freeze a few till you get one giant out with a duplicate and most zoo will smash it which just generates more for you, loathe can't even stop the molten rush

This card could end up being played by Mad Scientist on turn 2.  If he's killed during your opponent's turn, you'd end up with 2 mad scientists in your hand and potentially run out of secrets.  If they were ice barriers and ice blocks, that's fantastic.  If they're anything else, that would be a bad scenario.  If he whiffs (no secrets left), then you duplicated an extremely lackluster card.

my opinion:  Not synergistic with mad scientist unless you run precisely 1 duplicate and at least 2 ice block/ice barriers.

Assume you have this secret played, you also have several low health minions in play. The next turn the opponent plays something like holy nova or arcane explosion and kills them all. which minion would be chosen to duplicate? 

The one first summoned, like Redemption, I would guess.

Quote from Serkif1 »

Assume you have this secret played, you also have several low health minions in play. The next turn the opponent plays something like holy nova or arcane explosion and kills them all. which minion would be chosen to duplicate? 

If multiple minions die at the same time, the one to the far left is chosen as the triggering minion.  source: http://hearthstone.gamepedia.com/Duplicate

Thanks for that! very good info!