Can a continuous effect that gives haste wear off?

Question

For example, let's say I have a Thopter Engineer which has the ability:

Artifact creatures you control have haste.

I then cast an Artifact Creature. If my opponent were to cast Lightning Strike targeting Thopter Engineer in response, it would go on top of the stack and resolve first, destroying Thopter Engineer. The Artifact Creature would then resolve, enter the battlefield, and not have haste.

Otherwise if I cast the Artifact Creature with no response, it resolves, enters the battlefield, and gains haste thanks to Thopter Engineer's continuous effect. What would happen if I passed priority after this and my opponent decided to then cast Lightning Strike on my Thopter Engineer?

Would the Artifact Creature keep haste and be able to attack during combat that turn? Or would it lose haste due to the continuous effect no longer applying and not be able to attack?

Answer 1

The Artifact Creature would lose haste if the Engineer was destroyed because it is a continuous effect from a static ability whose source has disappeared. As you mentioned, this means the creature will be unable to attack this turn.

The one difference in your two scenarios is that in the second one, if the Artifact Creature had an activated ability with the tap or untap symbol in its cost, it could use that ability in response to the Lightning Strike being cast against the Engineer.

Answer 2

It actually doesn't matter which ability resolves first. Thopter Engineer's ability is a static ability, and it only functions while he is on the battlefield. If he leaves the battlefield, the ability goes with him, and any creatures that had haste because of him will no longer.

112.3d Static abilities are written as statements. They’re simply true. Static abilities create continuous effects which are active while the permanent with the ability is on the battlefield and has the ability, or while the object with the ability is in the appropriate zone. [...]

Comprehensive rule 604.2 says the same thing, almost verbatim.

Answer 3

Rainbolt was a little bit off, and i don't think he understood the difference between the two scenarios. If Thopter Engineer is on the battlefield, and you cast an artifact creature (Let's say Memnite), that artifact creature goes on the stack. Now if your opponent lightning bolts your Thopter Engineer in RESPONSE, the lightning bolt resolves first and kills the thopter engineer, so the Memnite(when it resolves) will not have haste. If they let the Memnite resolve before they lightning bolt the Thopter Engineer, the memnite will have haste as long as the lightning bolt is still on the stack, allowing you to use it for something like convoke or opposition before the thopter engineer dies and the Memnite loses haste. Sorry for long explanation lol.