Welcome back to Eye of the Stack! Last time we broke down what happens when Mirrorweave mixes with all kinds of different creatures, but now it’s time to take the next step. Sometimes Mirrorweave can target a creature that isn’t a creature card!
Mirrorweave only needs two things to be true in order to resolve successfully: it needs to be targeting a creature, and that creature can’t be legendary. When it resolves, each creature Mirrorweave is not targeting becomes a copy of the targeted card. That means that if I control a basic Plains enchanted with Wind Zendikon, and I cast Mirrorweave targeting the Plains, each creature on the battlefield will become a basic Plains! Those Plains are not creatures (unless they have another effect making them into creatures) because the effect of Wind Zendikon is not copied by Mirrorweave.
If the Zendikon is on a Contested War Zone*, and I resolve Mirrorweave targeting it, each other creature will become a non-creature copy of Contested War Zone until end of turn. If you hit your opponent with your animated land, you gain control of each Contested War Zone your opponent controls. Then at the end of the turn, those War Zones turn back into the creatures they once were and you still control them! That’s because the control-changing ability of Contested War Zone creates something called a “continuous effect”.
611.2a A continuous effect generated by the resolution of a spell or ability lasts as long as stated by the spell or ability creating it (such as “until end of turn”). If no duration is stated, it lasts until the end of the game.
When it resolves, Contested War Zone‘s ability changes its controller until the end of the game. This is very easy to grasp, but when several continuous effects overlap, it can create hard-to-track rules situations. To resolve these situations, we need to understand something the Magic rules refer to as “layers”. There are seven layers through which we apply continuous effects:
613.1a Layer 1: Copy effects are applied. See rule 706, "Copying Objects."
613.1b Layer 2: Control-changing effects are applied.
613.1c Layer 3: Text-changing effects are applied. See rule 612, "Text-Changing Effects."
613.1d Layer 4: Type-changing effects are applied. These include effects that change an object’s card type, subtype, and/or supertype.
613.1e Layer 5: Color-changing effects are applied.
613.1f Layer 6: Ability-adding effects, ability-removing effects, and effects that say an object can’t have an ability are applied.
613.1g Layer 7: Power- and/or toughness-changing effects are applied.
To determine the characteristics of an object, we start with the printed values of the card. Then, continuous effects are applied one at a time, by layer and timestamp, until all effects are accounted for. This means that an effect at a higher layer, or with a newer timestamp, takes precedent over previous effects. The layer system creates far too many funky interactions to write about them all today, but I hope to cover the basics in this article!
Remember back in the beginning of the article, when I had a basic Plains enchanted with Wind Zendikon? Let’s say my opponent controls no creatures with flying, so I attack with my 2/2 flying Plains. My opponent activates their Celestial Colonnade, making it a 4/4 creature with flying and vigilance. Before moving to Declare Blockers, I resolve a Mirrorweave targeting my Plains, hoping to nullify my opponent’s new flying blocker. What happens? Unfortunately, things don’t go well for me. Mirrorweave does turn Celestial Colonnade into a basic Plains, but Colonnade’s ability creates a continuous effect! Referring back to the list of layers, we can see that Mirrorweave‘s Copy effect is all the way down at layer 1, meaning it applies first. Then, up at layer 4, Colonnade’s ability turns that Plains into a “Creature – Elemental”. Layer 5 brings the colors white and blue to the party, then layer 6 adds flying and Vigilance. Finally, layer 7 makes the creature a 4/4. In the end, the only result of my Mirrorweave is that my opponent’s 4/4 flyer is now named Plains and has the supertype “Basic”.
HEADACHE WARNING AHEAD
Proceed with caution
For this last example, we’re going to get really weird. I couldn’t find just one interaction to illustrate and explain everything I wanted to say about timestamps and dependencies, so I decided to add cards together until I’ve made my point! Let’s start with a Chimeric Staff. If I use Chimeric Staff‘s ability to make it a 1/1 creature, then Mirrorweave it, all other creatures will become noncreature Chimeric Staffs. Easy! Now let’s add March of the Machines to the battlefield. Each noncreature artifact on the battlefield will become a creature, meaning all those copies of Chimeric Staff become 4/4. But what about the Chimeric Staff we activated earlier? To answer that, we need to look at timestamps. Here are the two most relevant rules about timestamps:
613.6. Within a layer or sublayer, determining which order effects are applied in is usually done using a timestamp system. An effect with an earlier timestamp is applied before an effect with a later timestamp.
613.6a A continuous effect generated by a static ability has the same timestamp as the object the static ability is on, or the timestamp of the effect that created the ability, whichever is later.
March of the Machines‘ ability only applies to noncreature artifacts. Chimeric Staff‘s ability causes the Staff to become an Artifact Creature, and it has an older timestamp than March of the Machines, so March of the Machines will not apply to our 1/1 Chimeric Staff until the Staff’s ability ends at the end of the turn.
Now let’s say my opponent activates one of those copies of Chimeric Staff for 10 mana. The activated ability will have a newer timestamp than March of the Machines, so it will replace the 4 power and 4 toughness given to them by March of the Machines with 10 power and 10 toughness.
Now I cast Imprisoned in the Moon targeting my opponent’s 10/10 Chimeric Staff. When it resolves, it does not remove any continuous effects on the enchanted permanent; it simply has the newest time stamp, which means its ability overwrites all other types and abilities. This is important to note because…
…after Imprisoned in the Moon resolves, my opponent taps Liquimetal Coating to make the enchanted permanent (which is now a colorless land) into an artifact. This brings us into the final weird layers rule: Dependency! If we looked at everything by timestamp, turning this land into an artifact would not cause anything else to happen. However, the effect of March of the Machines is “dependent on” the Liquimetal Coating effect, which changes things. Here’s some relevant info from the comprehensive rules:
613.7. Within a layer or sublayer, determining which order effects are applied in is sometimes done using a dependency system. If a dependency exists, it will override the timestamp system.
So timestamps are overridden by dependency, but what is a dependency? Let’s look at this excerpt from the rules that defines dependent effects:
An effect is said to "depend on" another if (a) it’s applied in the same layer... as the other effect; (b) applying the other would change the text or the existence of the first effect... An effect dependent on one or more other effects waits to apply until just after all of those effects have been applied.
March of the Machines‘ ability only affects Chimeric Staff if it’s an artifact and it’s also not a creature. Several effects currently applying to the Staff alter those types, so before we determine whether March of the Machines‘ ability applies, we need to resolve all other relevant effects at layer 4 in timestamp order. First, we have the effect from Chimeric Staff‘s ability, making it an artifact creature until end of turn. Next is Imprisoned in the Moon, which adds the land type, then removes all other types. Finally, Liquimetal Coating makes that land into an artifact land. Now that those effects have all been applied, it’s time to try to apply March of the Machines and… voila! Since the Staff is an artifact, and it isn’t a creature, March makes it an artifact creature! It is still a land, thanks to Imprisoned in the Moon.
Now that we know the Staff is a creature, we can look at layer 7 – Power and Toughness. There are two power/toughness effects on the Staff, and none are dependent, so they will apply in timestamp order. The first is March of the Machines, making our land artifact creature into a 4/4, followed by the effect from Chimeric Staff‘s ability, which makes it a 10/10!
That was a heck of a lot of work to get through, but it was worth it because we’re leaving this article with a much better understanding of the layers system than we started with, and it’s all thanks to Mirrorweave!
Now I hear you out there, saying “Bob, the majority of this article had nothing to do with Mirrorweave whatsoever!” To that I say – True, but it was interesting. You’re welcome.
Thanks for reading, tune in next time when I’ll probably be three days late posting my article because the research takes so damned long!
*Special thanks to Reddit user Exkzol for letting me use his idea for this sweet Contested War Zone combo in my article!