Phyrexian Dreadnaught vs Basic Forests.

[LotusHead]

My opponent has a dedck with 60 Forests.
Mine is broken, and I play FLASH turn 1.

I Flash in 4 Phyrexian Dreadnaughts, with 0 cards in hand, and zero options. (I played Mox Sapphire and Forest myself.).

Is there any way to stack the Dreadnaught's sac 12 triggers so that I can have at least 1 in play post flash?

I am assuming no chance, since there are 4 Dreadnaught triggers that all need resolving, but...someone asked me, so I am posting here.

[Khahan]

Stack them any way you like.

{Dread A}
{Dread B}
{Dread C}
{Dread D}


Dreadnought A resolves and you must sac it unless you sac 12 power worth of creatures. So you sac Dreadnought C to satisfy it.  Dreadnought B resolve and you must sac it unless you sac 12 power worth of creatures. So you sac Dreadnought D to satisfy it. Dreadnought C resolves and you must sac it unless you sac 12 power worth of creatures. You decide to sacrifice it. The ability does nothing since the Dreadnought C  is not in play. Same thing goes for Dreadnought D.

~Oracle Text:
      Trample
When Phyrexian Dreadnought comes into play, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

[LotusHead]

Dreadnought C resolves and you must sac it unless you sac 12 power worth of creatures. You decide to sacrifice it. The ability does nothing since the Dreadnought C  is not in play. Same thing goes for Dreadnought D.
~Oracle Text:
When Phyrexian Dreadnought comes into play, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

I now see where the confusion comes in.  Previously, the ruling for dreadnaught says that you must TRY to sacrifice up to 12 power worth of creatures.  So if you had say, a LLanowar Elf, you would be FORCED to sacrifice it, even if you can't come up with 12 worth of creatures.

I'd still like and official official ruling on this.  I still think that initially, there are 4 dreadnaught's in play, and each ability demands a sacrifice of it, or 12 worth of dudes.  When C resolves, C is gone, but the demand for 12 is still there since you can't sac C at this point.

[Clariax]

Khahan's answer is correct, though the explanation is just a little bit off.  When the trigger resolves, you don't actually choose "sacrifice 12 power worth of creatures or sacrifice ~this~."  The choice is "Sacrifice 12 power worth of creatures or do not," with the result of choosing not to being that you sacrifice the dreadnaught.

The key is in the wording of the ability.  If the ability said "When Phyrexian Dreadnaught comes into play, sacrifice it or sacrifice any number of creatures with total power 12 or greater," then the choice of sacrificing it would not be legal were it not in play to sacrifice.

[LotusHead]

So the Dreadnaught trigger says...

Sac 12 power worth of creatures, or Don't?

There's no cumpulsory sac if you can?  If Dreadnaught C isn't in play when Trigger C resolves then choosing to "not saC 12, and hence sac Dreadnaught C" is a completly valid choice?  Even if Dreadnaught C isn't in play (due to Trigger A and Dreadnaught A is in play?

So I can, say, weld my Dreadnaught into play (getting rid of a troublesome Mana Crypt), and I can choose to Sac dreadnaught, and leave Welder alive?

If my opponent plays a dreadnaught (because I slavered him), can he sac 10 power worth of creatures ? (say, Platinum ANgel and Akroma)?

[Clariax]

The choice you make is "sacrifice 12+ power worth of creatures or don't."  You're not forced into making either decision (unless you don't have 12+ power worth of creatures that is).  Sacrificing 10 power worth of creatures is not a valid choice.  Sacrificing 22 power worth of creatures however (Angel, Akroma, Dreadnaught), is a valid choice.

[LotusHead]

Thanks for the concise and clear answers!