Flying Rule 702.9 Glossary

A keyword ability that restricts how a creature may be blocked. See rule 702.9, “Flying.”
Investigate Rule 701.16 Glossary

A keyword action that creates a Clue artifact token. See rule 701.16, “Investigate.”

Rulings (4)

April 8, 2016 Wizards of the Coast
If an effect refers to a Clue, it means any Clue artifact, not just a Clue artifact token. For example, you can sacrifice Wrench to pay for Alquist Proft, Master Sleuth's activated ability.
April 8, 2016 Wizards of the Coast
Casting a spell for an alternative cost, such as a madness cost, doesn't change its mana value. For example, casting Twins of Maurer Estate (a card with mana cost and madness cost ) for its madness cost will not cause Bygone Bishop's ability to trigger.
April 8, 2016 Wizards of the Coast
You can't sacrifice a Clue to pay multiple costs. For example, you can't sacrifice a Clue token to activate its own ability and also to activate Alquist Proft, Master Sleuth's ability.
April 8, 2016 Wizards of the Coast
Clue is an artifact type. Even though it appears on some cards with other permanent types, it's never a creature type, a land type, or anything but an artifact type.

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