Multiple-targeting spells.

[Harlequin]

If a spell/ability has multiple targets and ONE of those targets is made illegal, is the entire spell countered apon resolution or "Fizzle."

Exampe1: Dust to Dust targeting Uba Mask and Mox Pearl in play (only Mox Jet in the yard).  In Response my Opponent activates welder targeting Mox Pearl and Mox Jet.   What happens

Example 2: All of the above happens ... then In response (to the weld) I actiaved Tormod's Crypt targeting my opponent.  What happens now, is the pearl RFGed or in the GY.

Example 3:
I play Geae's Blessing targeting My opponent, and 2 squee's and darkblast.   in reponse My opponent actiavates Bazaar.  Bazaar resolves and my opp replaces the first draw with dredge on the darkblast (mills 3) then draws a card from his dec - then discards 2 cards + darkblast.  What happens? (do get to draw my card? where are the squees? where is the darkblast?)

[Matt]

A spell is countered upon resolution ("Fizzles") if ALL of its targets are illegal when it tries to resolve.

Example one: The Moxes get switched and then Dust to Dust removes Uba MAsk from the game.

Example two: The Crypt removes the Jet, the Welder ability fizzles (because it has been errata'd to have the text, "If both targets are still legal as this ability resolves," so it is not like most multitarget spells and abilities), and Dust to Dust removes both Pearl and Mask from the game.

If the Welder did not have that special errata text, the Jet would be RFG, the Pearl would be sacrificed, nothing would be Welded into play, and Dust to Dust would remove Mask from the game.

Example three: When Blessing resolves, it shuffles both Squees into your opponent's library, then you draw a card. The Darkblast has changed zones, so it is treated as a new object, and is no longer targeted by Blessing, so it stays in the graveyard.

[Harlequin]

So a Spell/Ability must have the wording
"If both targets are still legal as this ability resolves" in the errata in order for it to not resolve?

Wow ... you learn something new every day.  Thanks!

[Gort32]

So a Spell/Ability must have the wording
"If both targets are still legal as this ability resolves" in the errata in order for it to not resolve?

Wow ... you learn something new every day.  Thanks!

In essense, with Welder, the effect is a "trade."  While most spells/effects like Welder's (say, Tinker) include a sacrifice as part of its cost, with Welder putting the card into the graveyard is a part of the effect, not a cost, and occurs at the same time as the putting the artifact from the graveyard into play.  The errata on Welder makes so you cannot target a mox in play and an artifact in the graveyard, put the Welder ability on the stack, then feed the mox to, say Atog and still be able to get the artifact from the graveyard.  WIthout the errata this would be possible (and really really broken!).

[Harlequin]

Right I totally understood the welder.  And I understand the difference btwn additional cost, and part of an effect.   i just thought The welder ruleing applied to ALL cards that had multiple targets.  When I read the ruleing on welder i thought that the (targets must still be in the same zones) was a RULEING on every multi-targeting spell, when in fact it was a spesific ERRATA for a single card. 
Also look at cards like Mana drain, and artifact mutation etc... They fizzle completely when they have no legal target.  But Matt clearified that with his stress on ALL targets.  the secondary effect of mana drain and artifact mutation does not target and therefore when the target of mana drain or arti-mutation is gone, then ALL targets would be illegal and thus the entire spell (additional effects and all) would not resolve.

[asmoranomardicodais]

Wait... This isn't right. I was told by a judge at a prerelease that if I sacrificed a creature that was targeted by hex, so now hex only had five legal targets, hex would be countered. I'm pretty sure that a spell that doesn't have all legal targets fizzles.

Can someone tell me the judge is wrong, or back me up? Because now I am really confused

[Godder]

Oct 1, 2005 - You must target six different creatures. If you can't, you can't play Hex. If some of the creatures become illegal targets before the spell resolves, Hex will still destroy the rest of them.

The judge was wrong.

[asmoranomardicodais]

Damn, that makes hex slighty good. I was hoping it sucked, just like that judge pointed out to me.

Oh well, I would've won anyways, thanks godder.

[Godder]

Although I found the ruling in Gatherer (an excellent place for card-specific rulings, incidentally), it's actually from the Ravnica FAQ, so if it was the Ravnica pre-release, that would have been unfortunate .

[Evenpence]

Wow, I learned something new too.

I actually was playing Gifts the other day, and he cast Rack and Ruin on my Smokestack and Crucible as a last resort, I welded out the Crucible for a Mox Jet.

We both thought that the spell fizzled.  If it hadn't, he probably would have won.  It was game 3, too.

I'll have to tell him about this.