Under what circumstances do effects that modify the properties of permanents also apply to those which enter the battlefield later that turn?

Asked by SmugLookingBarrel 5 years ago

Why does Magmatic Chasm's effect also apply to creatures that enter the battlefield after it was cast, but Overrun's not? Is there a way to know whether a spell will apply to permanents that enter the battlefield later that turn?

Rhadamanthus says... #1

It depends on whether the effect changes the rules of the game or changes the characteristics of objects on the battlefield.

If it changes the rules of the game, then it affects everything, including objects that enter the battlefield after the effect has resolved. Magmatic Chasm adds the rule "creatures without flying can't block".

If it changes the characteristics of objects on the battlefield (name, mana cost, type, rules text, P/T), then the set of objects it applies to is locked in at the time it resolves. Overrun adds +3/+3 to the power and toughness of creatures on the battlefield and also gives them the "trample" ability.

September 21, 2018 7:12 p.m.

LGFlatron says... Accepted answer #2

Short answer:

• spells that have a continuous effect that modify the characteristics of objects (e.g Creatures you control get +3/+3 and gain trample until end of turn) will only affect objects that exist as the spell resolves.

• spells that have a continuous effect that don’t modify the characteristics of objects (e.g Creatures without flying can’t block this turn) will only affect objects that exist as the spell resolves.

The relevant ruling is 611.2c:

Ruling 611.2c Show

- 611.2c If a continuous effect generated by the resolution of a spell or ability modifies the characteristics or changes the controller of any objects, the set of objects it affects is determined when that continuous effect begins. After that point, the set won’t change. (Note that this works differently than a continuous effect from a static ability.) A continuous effect generated by the resolution of a spell or ability that doesn’t modify the characteristics or change the controller of any objects modifies the rules of the game, so it can affect objects that weren’t affected when that continuous effect began. If a single continuous effect has parts that modify the characteristics or changes the controller of any objects and other parts that don’t, the set of objects each part applies to is determined independently.

Note: Not everything is a characteristic, ruling 109.3 lists what counts as a characteristic:

Ruling 109.3 Show

- 109.3. An object’s characteristics are name, mana cost, color, color indicator, card type, subtype, supertype, rules text, abilities, power, toughness, loyalty, hand modifier, and life modifier. Objects can have some or all of these characteristics. Any other information about an object isn’t a characteristic. For example, characteristics don’t include whether a permanent is tapped, a spell’s target, an object’s owner or controller, what an Aura enchants, and so on.

The Gatherer rulings also support this:

Magmatic Chasm

• Because Magmatic Chasm’s effect doesn’t change the characteristics of any permanents, the set of creatures affected by Magmatic Chasm is constantly updated. Creatures without flying that enter the battlefield later in the turn won’t be able to block.

Overrun

• Overrun affects only creatures you control at the time it resolves. It won’t affect creatures that come under your control later in the turn.

September 21, 2018 7:27 p.m.