Welcome one and all! I’m pleased to welcome you all back to… unthemed… week… here on the Rules Tip Blog, and… wow, it’s weird not having a theme. That means I can do what I want, and you know what I want? More Izzet! Let’s do some more Izzet. As I’m sure you all know, the Izzet league is all about great ideas that don’t quite go right in the execution, and about SCIENCE! So, for your delight and delectation, please observe this very scientific tragedy in several acts:

An Izzet chemister sees Erratic Cyclops, a 0/8 with trample and “Whenever you cast an instant or sorcery spell, Erratic Cyclops gets +X/+0 until end of turn, where X is that spell’s converted mana cost.” The chemister wonders ‘Can I use Invert, which switches a creature’s Power and Toughness, to horribly break Erratic Cyclops?’, and forms a plan: cast Invert, triggering the Cyclops to make it a 1/8, which will be swapped to 8/1- and then, cast many more spells to make the Cyclops even stronger! To the chemister’s horror, all the spells they cast after Invert increase the Cyclops’ TOUGHNESS, rather than POWER! Poring over the results, the chemister decides that for whatever reason, whenever they try to increase the power of an Inverted creature, it increases toughness instead… and vice versa.

You’ll find this is true in your games of Magic as well. No matter when you cast Invert relative to other P/T boosts, you always swap the power and toughness of the target(s) last. Put another way, if you cast Invert and, for example, Sure Strike on the same creature, the creature will always end up with +0/+3 (and first strike). It doesn’t matter the order you cast the spells, the result is always +0/+3. Put another another way, if something has had its power switched, you work out what its power would be if you hadn’t switched it at all, then switch it right at the end. The upshot of all this is that it’s bad news if you’re trying to one-shot someone with your Erratic Cyclops, but good news if you’re trying to, for example, kill something that’s already been Inverted with Dazzling Lights!

This is the case for anything that changes power and toughness and anything that switches them- you apply all of the other changes before switching. The reason for this is an oft-maligned section of the rules you’ve probably heard of before- Layers. The power and toughness switching layer, 7e, is the very last layer, and most other power and toughness changing effects happen in an earlier layer: layer 7c. Because you apply all of the changes to a creature in the order of the layers, 7c happens first, then 7e- meaning that you swap power and toughness around last, no matter what. Another effect of this is that Inverting something twice will result in no change whatsoever, no matter when they were cast.

So with that dive into layers complete, it’s time for me to close the book on today’s unthemed Wednesday. Best of luck finding a way to blow someone up with your Erratic Cyclops, and please join us again for another unthemed tip on Friday!

(…still not used to it. Ah well. Who needs themes anyway!)

Today’s Rules Tip was written by Alistair Crook