Magus of The Moon and Urborg, Tomb of Yawgmoth

[Whit3 Ghost]

THis came up on MWS, and I thought that Moon would trump Yawgmoth.

Am I right?

[Nightmare]

THis came up on MWS, and I thought that Moon would trump Yawgmoth.

Am I right?You are. Urborg is considered a basic Mountain, which removes its ability to make things Swamps.

[Finn]

To be clear, it is not a basic mountain. It is a mountain. So it can still be Wastelanded, and it will still hurt if the opponent hits you with Price of Progress.

[gnurbel2000]

Under Magus of the Moon Wasteland is a Mountain too.

[Finn]

Damnit.

Fine, Friggin' Primal Order then.

:)

[cdr]

So why does an effect like Magus of the Moon's "win"?

It's not complicated - Urborg's effect is dependent on the Moon's effect.


418.5c An effect is said to "depend on" another if (a) it's applied in the same layer (and, if applicable, sublayer) as the other effect (see rule 418.5a); (b) applying the other would change the text or the existence of the first effect, what it applies to, or what it does to any of the things it applies to; and (c) neither effect is from a characteristic-defining ability. Otherwise, the effect is considered to be independent of the other effect.

418.5d An effect dependent on one or more other effects waits to apply until just after all of those effects have been applied. If multiple dependent effects would apply simultaneously in this way, they're applied in "timestamp order" relative to each other. If several dependent effects form a dependency loop, then this rule is ignored and the effects in the dependency loop are applied in timestamp order.

Since the Moon's effect changes the existence of Urborg's effect, Urborg's is dependent on the Moon's, and the Moon's is always applied first.

(More specifically, they do both apply in the same layer [(4) type-, subtype-, and supertype-changing effects], and neither is a Charactistic-Defining Ability [405.2] - an ability is a CDA only if, among other things, the ability applies only to its source).

[RoddyVR]

wow... Akki, that made it so much more complicated... I'm glad i try not to read the comp rules too much... You rules junkies amaze me sometimes with the amount of effort you put in to the finer points of the rules.

When i first saw the original question i didnt understand what the confusion was about or why it needed an explanation....

No matter if you apply the tomb first or the moon first, the end result is the same.

Moon first:
Urborg is a mountain, so no other effect to apply.

Urborg first:
All lands are swamps now (but this effect isnt permanant, it would go away if urborg is destroyed for example)
So when the moon is applied afterwards, and urborg turns into a mountain, all otherlands would lose their swampiness cause there would no longer be anything in play granting it.

there's probably some much more complicated aplications of this sort of stuff that would require that dependency rule though (that i still dont understand even after reading it, lol, not that i'm trying too hard).

[Anusien]

So when the moon is applied afterwards, and urborg turns into a mountain, all otherlands would lose their swampiness cause there would no longer be anything in play granting it.
Sounds good except that the rules don't actually work that way. Applying characteristics and abilities is a single-pass thing. You don't apply something and go back and look what has changed. The way of avoiding that is the dependency rules Akki quoted.