Bloodmoon and Urborg

[thefreakaccident]

I know now that if you have magus of the moon and humility in play although the magus technically should lose its' ability, and yet all non-basic lands are still mountains... I was wondering what happes when you have both magus of the moon and urborg, as it seems to have the same thing going on as the humility+magus...

Question:

What happens if you have an urborg, tomb of yawgmoth in play and your opponent has a bloodmoon effect on board as well?

[Taurelin]

Urborg and Blood Moon are another famous example of how layers work. However, in this case it works a bit differently than with Humility.

So let's assume we have both Urborg and Blood Moon in play.

Let's go through the layers:

(1) copy effects
-> nothing

(2) control-changing effects;
-> nothing

(3) text-changing effects;
-> nothing

(4) type-, subtype-, and supertype-changing effects;
-> Urborg's effect and Blood Moon's effect

(5) all other continuous effects, except those that change power and/or toughness;
-> nothing

(6) power- and/or toughness-changing effects.
-> nothing.

So both relevant effects apply in the same layer. Normally, the timestamp rule would work here to determine in which order they apply, but:

418.5a [...] Note that dependency may alter the order in which effects are applied within a layer or sublayer. [...]
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.

Are both effects in the same layer? Check.
Would applying Blood Moon first change the existence of Urborg's effect? Check!
Is it correct that none of the effects is from a CDA? Check.

Therefore, Urborg's effect is dependent on Blood Moon. What happens in such a case?


418.5d An effect dependent on one or more other effects waits to apply until just after all of those effects have been applied.

That means, no matter in which order the cards come into play, you always apply Blood Moon first. Then Urborg's effect will cease to exist, and all non-basic lands are Mountains and no Swamps.

[thefreakaccident]

Thanks for the help, glad to clear that one up :)