9 Feb 2017
An ability whose cost is simply {0} can be activated as many times as you'd like. Each activation causes Crackdown Construct's ability to trigger.
9 Feb 2017
Crackdown Construct's ability doesn't trigger if you activate an ability of an artifact or creature card not on the battlefield.
9 Feb 2017
An activated mana ability is one that could add mana as it resolves, doesn't have a target, and isn't a loyalty ability.
9 Feb 2017
Activated abilities are written in the form "Cost: Effect." Some keyword abilities, such as equip and crew, are activated abilities and will have colons in their reminder texts.