No. Assembling a contraption is a game action. It can be caused by the effect of a resolving spell or ability, but could be done as a cost, too, or by a state based action if replaced by such an effect (not that such cards actually exist right now, but the possibility is there). Compare to discarding a card, or tapping a permanent.
Can Contraptions be countered by cards like Cancel?
The creation of one can be, if it is done by a spell. Or an ability, if the counterspell allows to counter abilities. Also, contraptions create triggers when cranked, so something able to counter triggers can stop a cranked contraption's effect.
Does the cranking of Contraptions create a stack, abling the opponents to respond?
There is only one stack in the game and it always exist, though at many times it is empty. So technically no, it does not create a stack. But it adds an object to the already existing stack. And yes, players can respond to any object that's being put on the stack, a contraption's trigger is no exception.
Are Contraptions spells?
No, they are permanents (artifacts to be more precise).
Can Contraptions be countered by cards like Cancel?
Does the cranking of Contraptions create a stack, abling the opponents to respond?
Are Contraptions spells?
No. Assembling a contraption is a game action. It can be caused by the effect of a resolving spell or ability, but could be done as a cost, too, or by a state based action if replaced by such an effect (not that such cards actually exist right now, but the possibility is there). Compare to discarding a card, or tapping a permanent.
The creation of one can be, if it is done by a spell. Or an ability, if the counterspell allows to counter abilities. Also, contraptions create triggers when cranked, so something able to counter triggers can stop a cranked contraption's effect.
There is only one stack in the game and it always exist, though at many times it is empty. So technically no, it does not create a stack. But it adds an object to the already existing stack. And yes, players can respond to any object that's being put on the stack, a contraption's trigger is no exception.
No, they are permanents (artifacts to be more precise).
You may want to read the Un-Stable release notes:
https://magic.wizards.com/en/articles/archive/news/unstable-faqawaslfaqpaftidawabiajtbt-2017-12-06
Former Rules Advisor
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