Finally for this week’s Gatecrash mechanics, we have House Dimir, the blue-black masters of stealth and subterfuge. Their mechanic this time around is called Cipher, and boy is it a doozy! I’ve gotten plenty of questions about Cipher, so I’ll answer some of them for you here.

Cipher is a fun mechanic. When a spell with Cipher resolves, you have the option to exile the card ‘encoded’ on a creature you control. Whenever that creature deals combat damage to an opponent, you can cast a copy of the encoded spell, for free! This lets you double, triple, even quadruple your fun by getting to use the same spell over and over as many times as your creature can connect. Unlike most copy effects [think Reverberate or Twincast], Cipher has you create a copy of the card in exile and cast that, so it’ll trigger things that care about a spell being cast. Big question number one: No, you can’t encode the copies onto a creature. The rules for Cipher say that you only get the option to Encode it if the spell is represented by an actual card, while the copy is not.

Big question number two: Yes, you can and should be encoding as many spells as possible onto your Dimir Keyrunes. The rules for Cipher also tell us that the duration is ‘as long as the card with cipher remains exiled and the creature remains on the battlefield’, and that it doesn’t matter if that creature stops being a creature for a while. So you can slap a Last Thoughts on your keyrune and draw a card every single time it connects.

And yes, if your encoded creature has double strike, you get to cast the encoded spell once for each combat damage step! That means double casting your cipher spell each time your double-striker goes unblocked! However, remember that cipher only triggers on combat damage, so you can’t draw free cards with Last Thoughts on your Bomber Corps when it’s battalion ability deals damage.

Today’s Rules Tip written by Trevor Nuñez