Creature Type Nonsense - Goblin Goblin Goblin Goblin Goblin.

[Tacosnape]

Alright, so, here's the posish.

My opponent has out a Mirror Entity and two Goblin Kings.

He tries to activate the Mirror Entity's ability for :1: four separate times. His argument is that each time he activates the Mirror Entity, his creatures gain the Goblin creature type. Therefore, if he activates this four times, each of his creatures are for lack of a better term, Goblin Goblin Goblin Goblins (Or Goblin Goblin Goblin Goblin Goblins in the case of the Kings), meaning the Mirror Entity would get +8/+8 (+2/+2 for each time it's a Goblin), and each King would get +5/+5.

I know this is completely ridiculous, but he asserts it and demand I show him the rule in the rulebook that disproves it. And I can't find it.

Can anyone verify I'm right and show me the relevant rule?

[Barook]

This is actually stupid. Multiple First Strike doesn't make your creatures faster than fast, too. The keyword "Changeling" is key here:


502.73. Changeling

502.73a Changeling is a characteristic-defining ability. “Changeling” means “This object is every creature type.” This ability works in all zones. See rule 405.2.

502.73b Multiple instances of changeling on the same object are redundant


What he can do, however, is paying :4: instead, making all his Goblins 4/4s and then they get the +2/+2 bonus (+1/+1 for Kings).

[Zuriya]

Well, the creatures get all creature types, but they don't get changeling.
But you are right nevertheless.

[Drathro]

I'm not sure what the rule is on redundant creature types, but the point is irrelevant because, to my knowledge, there are no spells or abilities which ask how many times a creature is defined as a type, only if a creature is a type or not.

For example, Goblin King reads:

Other Goblin creatures get +1/+1 and have mountainwalk.
This doesn't mean each creature gets +1/+1 for each time it is a Goblin, it means that each other creature which is a Goblin gets +1/+1 (and Mountainwalk). Essentially, the ability asks, "Is this creature a Goblin?" Acceptable answers are "Yes" or "No." "Yes times four" is not an acceptable or relevant answer.

Unfortunately, I don't have a reference to a rule to make this iron-clad. I'm sure one of the resident judges can help.

[zulander]

From the Oracle rulings regarding Mirror Entity:
Activating the ability for a second time in the same turn will overwrite the first activation.

That's all that I could find, although the rest of the oracle info regarding mirror entity is pretty useful.

[Lego]

First, Drathro was correct. If you happen to make a creature a Goblin Goblin Goblin Goblin Goblin, it would still only get the benefit from Goblin King once. It's a Goblin, so it gets the benefit. Goblin King would have to have an incredibly clunky wording to bestow the benefit more than once. Something crazy like, "Other Goblin creatures have mountainwalk and get +1/+1 for each instance of the Goblin subtype they have." AFAIK, no cards like this exist, so having a second instance of a subtype is redundant.

Second, the relevant rule in Mirror Entity's case is 212.1b:


When an object’s card type changes, the new card type(s) replaces any existing card types. Counters, effects, and damage affecting the object remain with it, even if they are meaningless to the new card type. Similarly, when one or more of an object’s subtypes changes, the new subtype(s) replaces any existing subtypes from the appropriate set (creature types, land types, artifact types, enchantment types, planeswalker types, or spell types). If an object’s card type is removed, the subtypes correlated with that card type will remain if they are also the subtypes of a card type the object currently has; otherwise, they are also removed for the entire time the object’s card type is removed. Removing an object’s subtype doesn’t affect its card types at all.

I've highlighted the relevant part. Except for Mistform Sliver, every creature type change I know of overwrites previous changes. For it not to do so, it would have to say, "in addition to its other types" or something to that effect.

[Drathro]

Similarly, when one or more of an object’s subtypes changes, the new subtype(s) replaces any existing subtypes from the appropriate set
Even though I agree with the overall idea, does this really explain Mirror Entity?

Mirror Entity says that your creatures gain all creature types, rather than that they are all creature types. Unfortunately the word "gain" doesn't usually apply to adding creature types, so it's a little ambiguous. (Usually adding a creature type is worded as "the creature is a <new type> in addition to its other types.")

[Lego]

Even though I agree with the overall idea, does this really explain Mirror Entity?

Yes, it applies to Mirror Entity. The default mode for a type change (in this case, adding a creature type is a change to the object's creature types) is to simply overwrite the old type. Unless the effect specifies otherwise, any type change will overwrite previous types from the same set. This is why so many cards say, "in addition to its other types," because if they didn't, they would revert to the default: overwriting.