Continuous effects

Nothing is more intricately intertwined with the reputation of a rules expert than a solid knowledge of continuous effects. A lot of information to remember combined with some counterintuitive interactions and a set of rules that have changed several times in Magic’s history combine to make them the putative most difficult rules topic. But there’s no reason to be intimidated! You might not ever say that they’re easy, but after becoming familiar with the system that governs their interactions, they should at least make sense.

If you’re a visual learner, you may want to check out the conference presentations page, where you can find my presentation about continuous effects.

In a nutshell:

  • Continuous effects apply instantaneously and are updated all the time. They aren’t like state-based actions or triggered abilities that wait to apply until someone gets priority. Example: If you control Darkest Hour and cast a Grizzly Bears, the game sees a black creature enter the battlefield. It doesn’t enter the battlefield and then become black. As soon as it hits the battlefield, it’s black.
  • Continuous effects apply in a series of layers. Effects that do any of the following things apply in the order dictated by the layers. For example, all copy effects always apply before all control-changing effects. This is the part people have the most trouble with because it’s just rote memorization. These are the layers in order:
    • Copy effects
    • Control-changing effects
    • Text-changing effects
    • Type, subtype, and supertype-changing effects
    • Color-changing effects
    • Ability-adding or -removing effects
    • Power/toughness effects, which are applied in sublayers in the following order:
      • Characteristic-defining abilities
      • Base p/t setting effects
      • P/t buffs and debuffs (think +1/+1 and -1/-1 effects)
      • P/t buffs and debuffs that come from counters
      • P/t switching effects
  • If a continuous effect would apply in more than one of these, apply each part in its appropriate layer.
  • If a continuous effect begins to apply in one layer or sublayer, all parts of that effect will apply to the same set of objects in each subsequent layer or sublayer, even if the set of objects it wants to apply to changes or it loses the ability generating that effect during the process.
  • If two continuous effects would apply in the same layer (and, if applicable, sublayer), the one with the earlier timestamp (the one that started first) is applied first.
  • If two objects would both get a timestamp at the same time, the active player chooses the order.
  • The timestamp rule is superseded if there is a dependency. Continuous effect A is dependent upon continuous effect B if they are applied in the same layer (and sublayer) and applying B before A would:
    • Change the set of things that A applies to,
    • Change how A affects any of those things, or
    • Change the text of A or whether it exists.
  • If continuous effect A depends on continuous effect B, B applies before and A applies directly after it.
  • If there’s a dependency loop (A is dependent upon B, and B is also dependent upon A), ignore the dependency rule and go by timestamps.
  • There are other kinds of continuous effects that don’t have to do with setting an object’s characteristics, and so don’t fit into the layers. For example, Thought Nibbler or Berserkers of Blood Ridge. These are applied in timestamp order. The exception to this is…
  • Some continuous effects affect costs. For example, Suppression Field, Thornscape Familiar, or Trinisphere. These are applied in the following order: Effects that increase the cost first, then effects that reduce the cost, then effects that set the cost.

One thing I think puts a lot of people off is that the complexity of this system is often perceived as gratuitous. Why can’t we just apply all the continuous effects in timestamp order? The goal of the continuous effects system is to make it so the answer to any continuous effects question is what we would intuitively expect as often as possible. For example, Copy Enchantment would not work on a card like Control Magic if control-changing effects could be applied before copy effects. That wouldn’t make any sense! This is why we need layers. As you read through the examples here, before reading the answers, think about what you would expect the answer to be if you were playing a game and this came up.

Q: What mnemonic do you use to help you remember all those layers?

A: I always recommend that people make up their own mnemonic because that makes it more meaningful to you and easier to remember. The first such mnemonic I heard referenced the TCAP, a standardized test given to students in Tennessee. It worked great for the judge who told it to me (who was a teacher from Tennessee), but not as well for me. It’s not particularly hard to come up with a sentence in which the first letter of every word spells out CCTTCAP, so give it a try. Sentences that evoke vivid images, particularly humorous, violent, or sexualized ones tend to work well because they’re easier to remember.

If you really aren’t a creative type, one of the best I’ve heard is the “three C’s of judging”: Commander, Clean Table Trash, Complain About Players. Another good one is CoPs CaN TaX TiPs CoLlected At Parties, which is less memorable, but the second consonants can be used to differentiate when the first letters are the same. If you’ve been through my L1 prep material, you’re already familiar with my mnemonic TOADS, which stands for Tarmogoyf, Omnibian, Auger Spree, Decree of Savagery, Strange Inversion for the sublayers.

Q: Amy controls a Night of Souls’ Betrayal and casts a Grizzly Bears. Will the Sword of the Meek in her graveyard trigger?

A: Yes. Because continuous effects apply continuously, there’s no point at which the bear is on the battlefield that it’s not getting -1/-1. It never exists as a 2/2 creature. For this reason, the sword will see a 1/1 creature entering the battlefield and will trigger.

Q: Nicole casts Humble on Amy’s Godhead of Awe. How big are the other creatures?

A: Humble strips the godhead of its abilities in layer 6. In layer 7, Humble sets godhead’s base p/t to 0/1. By this point, the godhead no longer has the ability that makes other creatures 1/1, so that doesn’t happen.

Note: Have you ever wondered why all the cards that make creatures lose all abilities always set the base p/t also? It’s because some creatures depend on their abilities to set their power and toughness. For instance, if Maro was hit by such an effect, its power and toughness would be undefined.

Q: Amy enchants Nicole’s Volrath’s Shapeshifter with Control Magic. The top card of Amy’s graveyard is Grizzly Bears, while the top card of Nicole’s graveyard is Hill Giant. What is the shapeshifter’s p/t?

A: If you’ve ever looked at the Oracle wording of Volrath’s Shapeshifter, you might have wondered why they changed it. Why can’t it just be a copy of a card in the graveyard like Body Double? If this were a copy effect, it would apply in layer 1, before control-changing effects. That would mean it would always look at its owner’s graveyard, which makes no sense. Wizards cleverly reworded this into a text-changing effect, which means it applies afterward in layer 3. The shapeshifter is a 2/2, just like you would expect.

Note: Many people get confused when working with text-changing effects. The most common issue is mistakenly identifying an ability-adding effect as a text-changing effect. Unless the Oracle wording or CR definition of the effect includes the word “text” (like Mind Bend, Volrath’s Shapeshifter, or the overload mechanic do), it isn’t a text-changing effect. Text-changing effects are pretty rare.

Q: Amy casts Humility, then Opalescence. What happens?

A: This famous rules quandary is actually pretty easy once you get the hang of layers. In layer 4, Humility becomes a creature due to Opalescence’s type-changing effect. In layer 6, Humility, because it now is a creature, loses all its abilities due to its own effect. In layer 7, there are two competing effects trying to set Humility’s p/t; Humility wants it to be 1/1, an Opalescence wants it to be 4/4. Humility’s effect still applies even though it lost this ability because it started to apply in layer 5 and will continue to apply to the same set of objects in each subsequent layer. Both Humility’s and Opalescence’s p/t-setting effects apply in sublayer 7b, and there is no dependency, so timestamps settle it. In this case, Humility entered the battlefield first, so it becomes a 1/1, then ends up a 4/4 after Opalescence applies.

Q: Amy casts Control Magic on Nicole’s Grizzly Bears. Nicole then casts Steal Enchantment on Amy’s Control Magic. What happens?

A: Both these effects occur in layer 2, so we check for dependencies. Applying Control Magic first doesn’t affect anything about Steal Enchantment’s effect, but applying Steal Enchantment first changes what player Control Magic assigns control of Grizzly Bears to. Therefore, Control Magic is dependent upon Steal Enchantment and is applied last. Steal Enchantment gives Control Magic to Nicole, then Control Magic applies and gives Grizzly Bears to Nicole.

Note: If we naively go by timestamps, we wind up in trouble. Control Magic, with its earlier timestamp would assign control of Grizzly Bears to Amy, and only then would Steal Enchantment take effect – but too late to do anything relevant. Nonsensical results like this are the reason why we need dependencies.

Q: Amy casts Blood Moon and then plays Urborg, Tomb of Yawgmoth. What happens?

A: Both these effects occur in layer 4, so we check for dependencies. Applying Urborg first doesn’t change anything about what Blood Moon will do, but applying Blood Moon before Urborg will make Urborg into a Mountain, removing its abilities. Because applying Urborg after Blood Moon changes whether Urborg’s ability exists, it is dependent upon Blood Moon and Blood Moon applies first. All nonbasic lands are Mountains. No lands are turned into Swamps.

Q: Amy controls a Forest and a Gutter Skulk as well as a Life and Limb and a Conspiracy for which “Saproling” is the chosen type. What are the characteristics of her permanents?

A: Both of Life and Limb and Conspiracy try to apply in layer 4, so we check for dependencies. Conspiracy depends upon Life and Limb because applying Life and Limb first makes the Forest into a creature, increasing the number of permanents Conspiracy applies to. On the other hand, Life and Limb also depends upon Conspiracy because applying Conspiracy first makes Gutter Skulk a Saproling, increasing the number of permanents Life and Limb applies to. The two continuous effects form a dependency loop, so we ignore dependencies and go by timestamps.

Suppose Conspiracy entered the battlefield first. Then it would apply first and make Gutter Skulk a Saproling. Then Life and Limb would apply and make both Gutter Skulk and Forest into Creature Land – Saproling Forests. In subsequent layers, Life and Limb would make both permanents green (layer 5) and 1/1 (layer 7).

Suppose now that Life and Limb entered first. Its effect would apply first, making only the Forest into a Creature Land – Saproling Forest. Then Conspiracy would apply and make Gutter Skulk a Saproling. In layer 5, Life and Limb would make the Forest green. Gutter Skulk would remain black because even though it is now a Saproling, it wasn’t when Life and Limb’s effect started to apply. Life and Limb will continue to apply to the same set of objects in each layer, even if the set of objects it wants to apply to changes along the way. In the same way, only the Forest will become a 1/1. The Gutter Skulk, though a Saproling now, will remain 2/2.

Note: If either Gutter Skulk or Forest wasn’t on the battlefield, there would be no dependency loop. In that case, the dependency rule would dictate which effect applied first.

Note: If this question seemed tough, that’s because it is. Don’t be intimidated! This question was specially selected to illustrate certain concepts (a dependency involving the set of affected objects changing, dependency loops, the set of objects a continuous effect applies to not changing even if new objects want to join that set along the way) and isn’t related to actual Magic: the Gathering in any way. You’re not going to see any Life and Limb/Conspiracy decks at your next modern tournament.

Q: Amy controls a Spellbook and a Recycle, and her opponent controls a Gnat Miser. What is her maximum hand size?

A: These continuous effects don’t affect the characteristics of any objects. That means they are all applied after layer 7 in timestamp order. If Spellbook or Recycle is last, that will set her maximum hand size. If Gnat Miser is last, her hand size will be 1 if Recycle is after Spellbook, and she won’t have a maximum hand size if Spellbook is after Recycle.

Q: Amy controls a Sphere of Resistance, an untapped Trinisphere, and four other artifacts. She wants to cast a Frogmite. What will total cost be?

A: Cost increasing effects apply before cost reducing effects, and cost-setting effects (which, to date, includes only Trinisphere) are applied last. So Frogmite starts out costing 4, which Sphere of Resistance increases to 5, then Affinity tries to reduce this to -1, but cannot reduce the cost below 0. Finally Trinisphere checks the cost, sees it is less than 3, and sets it to that much.