If I have Inventor's Goggles on the battlefield then play Metallic Mimic choosing Artificer as the creature type, do I get the option to attach the goggles to mimic for free?
Two questions really as this is a learning opportunity for me. The original card text says: "As Metallic Mimic enters the battlefield, choose a creature type." Does the answer to my first question change if the text said "WHEN Metallic Mimic enters the battlefield, choose a creature type." I know this second question is a little nit-picky, but trying to learn the difference between "as it enters the battlefield" and "when it enters the battlefield."
Yes. If you have Mimic become an artificer as it enters the battlefield, it will trigger Goggles and equip it. This works for the same reason Clone gets the ETB triggers of creatures it copies. "As it enters" replacement effects always are determined after a creature spell (or spell/ability putting it into play) has resolved, before a creature enters the battlefield.
Does the answer to my first question change if the text said "WHEN Metallic Mimic enters the battlefield, choose a creature type."
Yes. Effects starting with ''as'' are applied BEFORE the creature enters the field (rule 614.1c), while effects starting with ''when'' are applied AFTER (rule 603).
Two questions really as this is a learning opportunity for me. The original card text says: "As Metallic Mimic enters the battlefield, choose a creature type." Does the answer to my first question change if the text said "WHEN Metallic Mimic enters the battlefield, choose a creature type." I know this second question is a little nit-picky, but trying to learn the difference between "as it enters the battlefield" and "when it enters the battlefield."
Many thanks in advance!
RULES OF MAGIC :
http://magic.wizards.com/en/game-info/gameplay/rules-and-formats/rules