I f there's one thing to understand when you're on Mirrodin, it's the importance of footwear. Five suns, and the ground is made of metal? Those Mirrans must have some wicked heel calluses. Big, clanky heel calluses.

Glimmerpost | Art by Matt Cavotta

If there's a second thing to understand when you're on Mirrodin, it's how the Mirrans and Phyrexians behave differently. Just about every creature you'll encounter on Mirrodin is going to have an organic shape with metal components; you won't always be able to tell them apart from visuals alone. You need to be able to spot the differences, and then see past those surface features to understand the deep correspondences that determine them.

When a Mirran denizen encounters a creature in the shining, hex-plated wastes of the Glimmervoid, he doesn't have a watermark to guide him. He can peer at the creature all he likes (up to a point), but there's no single identifying characteristic that will be sufficient evidence to declare it either Mirran or Phyrexian. Most Phyrexians are horrifying flesh-and-metal monstrosities, but so, for example, are most vulshok before they've had their morning coffee. This goes for non-creatures as well—when a Mirran sees an artifact or an act of magic, there will be no reliable visual cue to guide him whether it's safe to be around it.

However, you can learn to recognize the signs. The signs are in behavior and in effects. Mirrans and Phyrexians have different goals, and behind the flavor of those goals are different mechanics—the way the cards work.

Know the signs. A card in Scars is Phyrexian if:

The card's rules text mentions poison.

The card's rules text mentions proliferate.

The card's rules text mentions -1/-1 counters.

The card is a creature with a "put into a graveyard from the battlefield" effect.

The card involves sacrificing creatures.

The card uses life as a payment.

(I stole this handy list from Mark Rosewater.)

On the other hand, a card in Scars is Mirran if:

The card's rules text mentions metalcraft.

The card's rules text mentions imprint.

There aren't as many hard-and-fast rules about what it takes to be Mirran. It's the Mirrans' plane, though—Mirrans are the default. If something lacks any of the major signs of being Phyrexian, it's Mirran ... probably.

Some patterns tend to suggest a card as Mirran, but there are exceptions. Being a Myr, for example, or being Myr-flavored (like Myr Reservoir), tends to make you on the Mirran side. Myr fight for their home plane of Mirrodin. But Ichorclaw Myr is an example of a Phyrexianized Myr—and being Phyrexianized is pretty much a one-way trip. There may be more examples that contradict the rules of Mirran thumb to come.

Ichorclaw Myr | Art by Eric Deschamps

An aside, on planeswalkers and watermarks: Note the planeswalker Venser, the Sojourner, the artificer and teleportation mage we last saw as the legend card Venser, Shaper Savant. And note Elspeth Tirel, a new version of Elspeth, Knight-Errant who we last saw on Bant. Those planeswalkers aren't from Mirrodin, and they lack a watermark. That was a conscious decision. Even Koth of the Hammer, a vulshok geo-mage who's native to Mirrodin, has no watermark. Koth is dedicated to fighting the Phyrexians for the survival of his world; he's clearly on the Mirran side. But planeswalkers don't get Mirran/Phyrexian watermarks. They're capable of planeswalking away from Mirrodin, and have a perspective that encompasses more than just the conflict happening on that one world. In a sense, while they're free to choose to fight for either side of this conflict, each planeswalker is essentially his or her own faction.

Flavors of Proliferation

The flavor of the proliferate mechanic is the spreading of the Phyrexian contagion. There are four main ways that Phyrexia spreads itself, embodied by the six proliferate cards in Scars of Mirrodin. Here they are in roughly ascending order of what you might call "intentionality."

Proliferation by the Glistening Oil

The Phyrexian oil, that black glisteny stuff that isn't literally a fossil fuel but certainly fuels reactions and pollutes life, is the first method of Phyrexian transmission. It's the smallest unit of Phyrexia-ness, the virus that spreads the Phyrexian identity code from entity to entity. As seen on Steady Progress, the oil can simply pool up like any other liquid, transmitting the Phyrexian contagion passively to anything that touches it.

Steady Progress | Art by Efrem Palacios

By the by, the vedalken of Lumengrid, race of knowledge-obsessed researchers that they are, have taken to studying this newfound oily substance. But don't worry—nothing bad will come of it. Seriously, there is no way that anything could possibly go horribly wrong as a result of the vedalken performing experiments involving the strange properties of the Phyrexian oil. No way that inoculating elvish test subjects with the oil could lead to—Instill Infection—except for the advancement of knowledge and learning. That's how science works—you do your experiments, you record the results, and day-by-day you make Steady Progress. So, you know. There's noooo. Reason to. Worry. About. That.

Proliferation by Phyrexian Machines

Phyrexia is a system founded on the power of the machine. Machines are not just tools for Phyrexia to manufacture their civilization and accomplish their goals; machines are fundamental to their beliefs. Phyrexia is a civilization of constant evolution, of self-betterment, of personal and global advancement, and artifice is the key to a Phyrexian creature's freedom from the confines of its organic origins.

Phyrexia solves any problem with a combination of evolution and artifice, and the problem of expanding its own civilization is no exception. Phyrexia creates machines to hasten the spread of its encroachment, such as Contagion Engine, or Contagion Engine's little brother, Contagion Clasp (the convenient proliferation artifact for today's on-the-go Phyrexian).

In the art of Inexorable Tide you can see a shot of some of the larger machines used by Phyrexia to corrupt the "waters" of the Quicksilver Sea. The Sea is one of the first areas beyond the Mephidross where Phyrexian oil has been introduced on a large scale; the area where this contamination has occurred is called the Darkslick.

Proliferation by Non-Sentient Creature

Phyrexia doesn't only spread itself by impersonal machines churning blindly away. Sometimes it gets frighteningly personal. Infect creatures, such as the first wave of Phyrexian creatures like Cystbearer or Contagious Nim, can serve as living disease vectors that introduce the Phyrexian oil into other living beings. But some Phyrexian horrors, only recently encountered by Mirrans, spread the contagion more subtly.

Thrummingbird | Art by Efrem Palacios

Creatures such as Thrummingbird serve to fan the flames of existing infection. They swoop in, carrying transmittable cocktails of mutating magic, causing creatures affected by phyresis to move to the next stage of "development." While certainly part of an evil civilization, thrummingbirds are not themselves truly evil, as they are mindless, birdlike Horrors, merely fulfilling the purpose for which they were created. If you see a Thrummingbird, you are not facing Phyrexia's true madness; your best hope is to swat the droning pest before it plies its contagious trade. Thus far, we've seen few creatures that work with thought, intention, and purpose to spread Phyrexia.

Proliferation by Sentient Action

But that doesn't mean that the dark, intentional forces aren't out there. Geth, lord of the whispering vault of Ish Sah, has allowed himself to become entangled with the encroaching threat of Phyrexia. Like any good black-aligned figure, he's actually acting in his own interests, but right now he sees the advancement of Phyrexia as expedient for his own ends.

Throne of Geth | Art by Jana Schirmer & Johannes Voss

Geth's minions, the trudging, cranially-plated, necrogen-infected zombies known as nim, bring offerings of metal to their master, which he in turn uses to further Phyrexia's cause. Geth's throne itself has become a symbol of Phyrexia's advancement, an altar for the sacrifice of the Mirran past in pursuit of a Phyrexian (and ultimately, he hopes, a Geth-friendly) future.

Will we see more proliferation in the future? Seems likely. It seems like a mechanic—and a viral strategy—that has yet to bloom to its fullest potential.

Letter of the Week

Dear Doug Beyer, I wanted to ask you a question to help settle a debate going between a friend and I. I must admit, Rise of the Eldrazi is one of my favorite sets in recent memory, which has given me a certain favoritism to the gigantic titans. With the return of the old threat of Phyrexia, there has been some talk about who is the true ultimate threat to the multiverse. The Eldrazi have sheer size and power, but Phyrexia have numbers and corruption. Could the Phyrexians corrupt an Eldrazi? The amount of time to corrupt something as powerful and large as an Eldrazi would surely take decades or even centuries-the same way it would take multiple turns to proliferate that single -1/-1 counter to put down a single Artisan of Kozilek. Or could the number of Phyrexians be enough to speed the process to a reasonable level? Or do the Phyrexians not care about speed, but more about efficiency? In the end I proposed a three player multiplayer match. One player would pilot an Eldrazi deck to represent the invading Eldrazi mammoths, one player will pilot an Infect deck to represent the Phyrexian hordes, and one player will play a third deck to represent the inhabitants of whatever plane the two are attacking. This could be a Kamigawa based deck, or a Lorwyn deck or just a Mirran deck. The point is they represent the stage fighting both back. This would be a fight for the plane, winner takes all. --C. Alex Figueroa

Note to self: Do not arrive third to Alex's house on Magic night.

"Okay, so, just to be clear—you're saying that there are three decks, and that—just making sure I have this right—you guys have chosen Phyrexia and the Eldrazi already? Sure. No, it's cool. Okay, turn three—cast Wall of Blood. Give it +20/+20. Who wants pizza?"

Finding a victim to play the "invaded" deck aside, the experiment is an interesting one. The Eldrazi are astral beings native to the Blind Eternities, the unreal realities between the planes, so maybe they wouldn't be susceptible to the Phyrexian contagion. But on the other hand, whenever the Eldrazi are manifested on an actual world, they seem to take physical form, and so maybe they can be affected just like any other living tissue. The Eldrazi legends can raise forces of Eldrazi Drones to serve them, but the Phyrexians can recruit minions by corrupting the plane's indigenous life. Annihilation and Spawn vs. infection and proliferation! WHO-oo-oo WILL-ill-ill WIN-in-in? (That's supposed to be a microphone with lots of reverb ... YEAH-eah-eah.)

In story terms, we regard the Eldrazi and Phyrexia as being on par with each other as villainous forces. They're both overwhelming powers able to harvest the life out of entire worlds—sort of like a stockpile of nuclear bombs, they're both fully capable of devastating a plane many times over. They're both more than a match for even teams of planeswalkers, and they're both good, nasty, enjoyably destructive bad guys to inflict on a storyline. The Zendikar storyline is over for now, but we still regard the Eldrazi as a major villain out there, waiting to inflict their obliterating hunger on some other hapless world. But which would triumph if they fought each other?

Nicol Bolas, Planeswalker, probably, somehow. BOLAS-olas-olas!

Enjoy proliferating some counters on permanents and planeswalkers. See you next week!