“Captain! I’m so glad you’re here; it’s a bad one.”

“What’s the situation, Sergeant?”

“Well, as you can see, we’ve got a single victim, Beast subtype. Middle-aged, so his CMC was probably 3 or 4, and there was definitely some red mana in his cost.”

“Has the medical examiner taken a look yet?”

“Yes, initial findings estimate that he had at least 3 power and 3 toughness, sir.”

“Any luck figuring out his rarity?”

“We’re pretty sure he’s not mythic, sir, but that doesn’t really narrow it down. There was something unusual, though…”

“What is it?”

“He was wearing a blocking restriction requirement when we found him, sir…as well as a blocking restriction.”

“No! Are you sure, Sergeant?”

“Yes, Captain — this Ember Beast was definitely Marked for Death.”

====

Suppose I’m playing against you in a Gatecrash draft. You control an Ember Beast and a few other creatures. Before combat, I cast Mark for Death on your Ember Beast, then attack into you with my Ruination Wurm. Can you block?

As it turns out, this situation will end up pretty ruinous for you.

When it resolves, Mark for Death creates two distinct effects. First, it demands that your Ember Beast block this turn. Second, it prevents all of your other creatures from blocking.

Ember Beast, however, has a third ability that’s also quite relevant: it can’t block by itself.

In judge parlance, effects that specify whether particular blocks are legal are classified as either “restrictions” or “requirements.” Restrictions are effects that prevent a creature from blocking, while requirements are any effects that force a creature to block. The game forces you to obey all restrictions, period. If you violate a single restriction, the Azorius will show up to say your block is illegal. On top of that, you also need to obey as many requirements as possible.

How we can classify the three effects involved here? Well, “Ember Beast must block” is clearly a requirement, and “other creatures can’t block” is also pretty obviously a restriction. “Ember Beast can’t block alone” is a bit weirder, but it has the word can’t, so it’s a restriction.

As a result, we have two restrictions — “Ember Beast can’t block alone” and “other creatures can’t block.” When we put those together, we perform the Magical equivalent of dividing by zero and end up realizing that nothing can block. The effect saying Ember Beast must block ends up doing nothing, because following that “requirement” would involve disobeying some restrictions.

Putting it all together, it’s impossible for you to block my Ruination Wurm, so you’ll be taking a hefty 7 damage.

(P.S. No Ember Beasts were actually harmed in the writing of this blog entry, because it couldn’t block anyway.)

Today’s Rules Tip/Drama was written by Paul Baranay