<p>You are able to activate it anytime you could cast an instant.</p>

<p>However once a creature has been declared an attacking or blocking creature the Vial's ability doesn't do anything, since it prevents a creature from being declared an attacker/blocker but doesn't undo that declaration.</p>

<p>From the Gatherer Rulings:</p>

<blockquote>
  <p>Activating the last ability of Alchemist’s Vial targeting a creature that’s already attacking or blocking won’t cause that creature to stop attacking or blocking. It will prevent that creature from attacking or blocking in any additional combat phases the turn may have (although this is unusual).</p>
</blockquote>

CC BY-SA 3.0
2016-02-12T18:20:01.520Z
2016-02-12T18:20:01.520Z
diego
<p>All activated abilities can be played anytime you could play an instant, unless the card specifically states otherwise.</p>

<p>Magic Comprehensive Rules:</p>

<blockquote>
  <p>112.3b Activated abilities have a cost and an effect. They are written as “[Cost]: [Effect.] [Activation instructions (if any).]” <strong>A player may activate such an ability whenever he or she has priority.</strong></p>
</blockquote>

<p>(Emphasis mine)</p>

CC BY-SA 3.0
2016-02-15T10:52:22.707Z
That's a surprising downvote. What did I do wrong? Is it the lack of comprehensive rules excerpt? Or the old "played" term instead of the new "activated"?
tsuma534
CC BY-SA 3.0
2016-02-15T10:59:39.677Z
I have included the relevant rule, but I'm leaving the wording unmodified. I consider it more accessible for the total newbies - the only group that might benefit from this question.
tsuma534
CC BY-SA 3.0
2016-02-15T13:46:11.103Z
It might be because you don't answer the entire question, they also ask about removing attackers/blockers after they have been declared
diego
CC BY-SA 3.0
2016-02-15T14:08:22.103Z
@diego Ah, thank you.

Well, that other part was presented as an "example" of the same situation, and I have treated it as an (unfitting) example, not as another question.
tsuma534
CC BY-SA 3.0
2016-02-13T09:15:10.663Z
2016-02-15T10:56:56.513Z
2016-02-15T10:56:56.513Z
tsuma534
<p>Can you use <a href="http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=398640" rel="nofollow">Alchemist's vial</a>'s ability as an instant, if you are able to pay the cost? For example, can it be used to prevent my creature from attacking, once i have declared it. </p>

<magic-the-gathering>
Alchemists Vial rules
steve cook
# Alchemists Vial rules

(Asked by: username_0 on 2016-02-12)

Can you use [Alchemist's vial](http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=398640)'s ability as an instant, if you are able to pay the cost? For example, can it be used to prevent my creature from attacking, once i have declared it.

**Tags:** magic-the-gathering


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## 2 answers

### Answer by username_1 on 2016-02-12. Score: 6

You are able to activate it anytime you could cast an instant.

However once a creature has been declared an attacking or blocking creature the Vial's ability doesn't do anything, since it prevents a creature from being declared an attacker/blocker but doesn't undo that declaration.

From the Gatherer Rulings:

> Activating the last ability of Alchemist’s Vial targeting a creature that’s already attacking or blocking won’t cause that creature to stop attacking or blocking. It will prevent that creature from attacking or blocking in any additional combat phases the turn may have (although this is unusual).


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### Answer by username_2 on 2016-02-13. Score: 0

All activated abilities can be played anytime you could play an instant, unless the card specifically states otherwise.

Magic Comprehensive Rules:

> 112.3b Activated abilities have a cost and an effect. They are written as “[Cost]: [Effect.] [Activation instructions (if any).]” **A player may activate such an ability whenever he or she has priority.**

(Emphasis mine)

> **Comments:**
> **username_2**: That's a surprising downvote. What did I do wrong? Is it the lack of comprehensive rules excerpt? Or the old "played" term instead of the new "activated"?  
> **username_2**: I have included the relevant rule, but I'm leaving the wording unmodified. I consider it more accessible for the total newbies - the only group that might benefit from this question.  
> **username_1**: It might be because you don't answer the entire question, they also ask about removing attackers/blockers after they have been declared  
> **username_2**: @username_1 Ah, thank you.  Well, that other part was presented as an "example" of the same situation, and I have treated it as an (unfitting) example, not as another question.  

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