Magic cards are like onions! (that is, what you need to know about the Layers) [ENG]
Magic cards are like onions!
(that is, what you need to know about the Layers)
(Partially in theme with the article, the parts in italics belong to a higher layer of study, so if you prefer to start slowly you can safely skip them)
"Magic cards are like onions"
"Do they stink?"
"Maybe some players, anyway NO!"
"Ah, do they make you cry?"
"Ah, you leave them in the sun and they turn brown and then white hairs show up?"
"NO!!! LAYERS! Onions have layers, Magic cards have layers "
Thanks to Shrek for this touching introduction, today we tackle a topic that is perhaps the most difficult at a regulatory level of all Magic: Layers. There are rather convoluted situations that in our format happen more often than in others (as you can see from the examples), and as always, a deep knowledge of the rules that govern those situations provides us with a decisive tactical advantage in the game. There are basically four things to know and they can only be simplified up to a certain point, so I'll go in order and try to be as clear as possible.
If your knowledge of the rules is very good, you will be able to find some (hyper?) simplification in the following, but on the other hand I hope you will understand why. In any case, for stranger and more pathological situations than those presented here, the definitive reference is the Comprehensive Rules.
First: Continuous effects, in Magic, interact with a system called “Layers”. To regulate the interaction of continuous effects, a real hierarchy has been established, the "Layers", in which every single continuous effect has a specific place according to its type. More precisely, every single part of every single effect belongs to its own Layer.
Having clarified this, when we have to try to understand what will be the final result of multiple continuous effects, just start from the "base" state of the object and apply the effects one after the other in order, starting from Layer 1. In particular, excluding rare exceptions that we will see in a while, you must NEVER think about which effect came before and which after: regardless of when the various effects started, they are applied in hierarchical Layer order.
This layered application is automatically and continuously applied by the game itself, so it is subject to "recalculation" whenever necessary. It is even faster than State-Based Generated Actions, so a creature that “halfway through” the calculation should have Constitution 0 won't die but the game will still wait for the end of the stack to see if it's still too thin to survive.
Second: the order of the Layers. Once you have clarified how the Layers work, what you need to remember is obviously in what order they are placed, or what is the hierarchy. And it is:
1) Rules and effects that modify the so-called “copiable values” of an object
1a) Effects of copying and "merging" objects
1b) Effect of being "face down"
2) Effects that modify the control of an object
3) Effects that modify the text of an object (replacing one color with another and things like that)
4) Effects that modify the type, supertype and / or subtype of an object
5) Effects that change the color of an object
6) Effects that add or remove abilities (including Ikoria's keyword tokens) or that prohibit an item from having a certain ability
7) Effects that modify a creature's power and toughness
7a) Effects that define power and toughness
7b) Effects that fix the “base” power and toughness at a specific value
7c) Effects (and counters) that modify power and toughness
7d) Effects that exchange power and toughness
The basic "copiable values" of an object are what is written on it, and are in fact modified by the effects of Layers 1a) and 1b). A consequence that it is good to keep in mind is that when we copy an object, we copy all and only the first layer of effects, the rest remains with it and that's it.
Layer 7a deserves a separate study, because obviously we are talking about Characteristic defining Abilities, another strange beast of the Magic rulebook. It is also worth noting the cumbersome presence of Ikoria among the Layers: between Trample tokens and mutated creatures, the rules have undergone major changes upon the release of that expansion.