What resolves first? Creatures abilities or instants? [duplicate]

Question

Can instants be played after I decide not to block?

I've been reading through this forum and google for this answer for a while now, the closest I have come to my answer is the thread linked above. Specifically this answer here. https://boardgames.stackexchange.com/a/12216/18889

Now to the specifics of the question. I'll use Longtusk Cub and Shock.

Opponent attacks with Long Tusk without pumping it up, leaving it at 2/2. I do not declare any blockers. Opponent decided to pay energy to make it a 3/3. In response, I cast shock.

Does shock take effect, since its an instant, before Long Tusk becomes a 3/3?

Thanks for the help in advanced.

Answer 1

Yes

In this example, the Longtusk Cub's pump ability is placed on the stack, Shock is placed on the stack and the stack resolves in reverse order. Shock deals 2 damage to a 2/2 creature, killing it; the pump ability fizzles as its 'target' is no longer on the battlefield.

A couple of comments on the way you've worded your question:

Does shock take effect, since its an instant, before Long Tusk becomes a 3/3?

The fact that Shock is an instant is irrelevant on when it will resolve, that's what the stack is for. The stack is what determines in what order effects are applied to the game. Shock being an instant allows you to place it on the stack at a good time - as a reaction to your opponent activating this pump-ability.

Also, in this case, it doesn't matter whether you declare blockers or not, or even if all of this is in the attack phase.