Q: "What is 'substance'? It appears in the Comprehensive Rules between Transmute and Bloodthirst and it says that it is a 'static ability with no effect'. What is this useless keyword, which has never appeared on a card, doing there?"
Davie, Florida, USA
A: From Mark Gottlieb, Magic Rules Manager:
"Useless??? Adam, just because substance doesn't do anything-or mean anything-doesn't mean it's useless. And as for appearing on no cards, well, I suggest you type it into Gatherer and see what pops up.
"Substance is the newest Mirage block keyword. Mirage and Visions each had a cycle of 'insta-chantments'-enchantments that you could play at the time you could play an instant. If you played one that way, though, you'd have to 'bury' it (we now say 'sacrifice' it) at end of turn. They worked great! Then a funny thing happened: The entire rules system was yanked out from under them. When the Sixth Edition rulebook was released, it reworked the end phase, and these cards didn't work so well anymore. Let's look at the difference:
"Mirage functionality: You play Shock targeting my Squire. I play Armor of Thorns on the Squire in response. Armor of Thorns enchants the Squire, it becomes 3/4, and 2 damage is dealt to it. At the end of the turn, the damage wears off and the Armor of Thorns goes away. The Squire lives another day.
"Sixth Edition functionality: You play Shock targeting my Squire. I play Armor of Thorns on the Squire in response. Armor of Thorns enchants the Squire, it becomes 3/4, and 2 damage is dealt to it. At the end of the turn, the 'sacrifice Armor of Thorns' ability triggers. It resolves, and Squire becomes a 1/2 creature with 2 damage on it because damage hasn't worn off yet. Squire dies. All Armor of Thorns did was delay the Shock damage, but it didn't save the creature.
"Why did this happen? Because the end phase is broken into two steps: the end of turn step (when all 'at end of turn' things happen), then the cleanup step (when all 'until end of turn' things stop happening). Damage that's been dealt to creatures wears off at the same time as the 'until end of turn' things stop happening. Armor of Thorns and friends worked under the new rules (they just worked differently and poorly), so they weren't changed.
"So these 10 Mirage block enchantments worked the first (good) way from 1996 to 1999, and they worked the second (crappy) way from 1999 to 2005-twice as long as they worked the original way. And no one noticed or cared. But then Mirage was released for Magic Online. Suddenly the functionality of these cards became relevant again, especially in Mirage limited formats. These cards were significantly worse than they were when they were first printed, they didn't work the way they were originally intended to work, and (worst of all) they didn't work the way players would think they worked.
"I was tasked with making these cards work the way they worked in Mirage, despite the fact that the rules don't support that kind of functionality. Various options were considered. Maybe the sacrifice ability triggers at the beginning of the next upkeep? Too much of a functional change, especially with phasing in the same set. Maybe these cards would only get their 'enchant creature' ability temporarily, so these Auras would fall off at the same time damage cleared, then be put into the graveyard as a state-based effect? Parapet (a Visions insta-chantment) isn't an Aura, so this solution wouldn't work for all of these cards. The 'sacrifice' ability needed to trigger during the cleanup step. My solution was to give these enchantments a dummy keyword ability until end of turn and an ability that would trigger when it lost that dummy ability. The dummy keyword is substance. And the result is that the sacrifice ability triggers and resolves during the cleanup step, after damage has cleared from the enchanted creatures.
"Current functionality: You play Shock targeting my Squire. I play Armor of Thorns on the Squire in response. Armor of Thorns enchants the Squire, it becomes 3/4, and 2 damage is dealt to it. During the cleanup step, Armor of Thorns loses substance and damage clears from Squire. Then the 'sacrifice Armor of Thorns' ability triggers. The Aura goes away, and Squire lives another day.
"The best part is that you can ignore everything I just wrote and just play these cards like you think they work… and you'll probably be right."