Rules Update: Split Cards

With the release of Amonkhet, we're getting a rules change due to the new aftermath split cards. Currently, the converted mana cost of a split card is simultaneously both of the converted mana costs of each half. For example, the converted mana cost of Breaking // Entering is simultaneously both two from Breaking and six from Entering.

But this is about to change. Once the rule officially updates with the release of Amonkhet, the converted mana cost of split cards will be computed as follows:

• When the card is on the stack, the converted mana cost will be the converted mana cost of the half that was cast.
• Everywhere else, the converted mana cost will be the combined converted mana cost of both halves.

So, 

• If Breaking is on the stack, the converted mana cost is 2.
• If Entering is on the stack, the converted mana cost is 6.
• If Breaking // Entering is on the stack (because you fused it), its converted mana cost is 8.
• If Breaking // Entering is in your hand, its converted mana cost is 8.
• If Breaking // Entering is in your graveyard, its converted mana cost is 8.
• If Breaking // Entering is in your library, its converted mana cost is 8.

Why This Matters

You're probably wondering why this matters, and the truth is that if you are playing split cards "fairly" (i.e., just casting them normally from your hand), you won't even notice this rules change. On the other hand, changing the converted mana cost of split cards does kill some decks that were playing these cards unfairly.

For instance, with a Brain in a Jar with two counters, you could cast either half of Breaking // Entering or Beck // Call, since the converted mana costs of the card were two. This change also impacts the Expertise cycle (which will no longer be able to cheat split cards into play with their "cast for free" ability), Goblin-Dark Dwellers (which can no longer flashback a Boom // Bust), and some other less popular cards as well. Moving forward, decks like Expertise Fuse Reanimator and Esper Bird Brains in Modern will simply no longer exist—abusing the converted mana cost of split cards was the entire plan of these decks. That said, the rule doesn't seem to be targeted at these decks specifically; rather, it's a combo of Wizards taking the aftermath cards as an opportunity to clean up a confusing rule and also to protect Standard from weird interactions between aftermath and things like Goblin Dark-Dwellers and As Foretold.

So, say goodbye to these Modern decks:

Card Types

Note, an Aftermath card is still "both types" when it comes to Torrential Gearhulk, meaning you can cast the Sorcery half of Destined // Lead off of a Torrential Gearhulk (anytime you could cast a Sorcery).