Quick Rules Question - The Stack (sigh)

[The Grim Reaper]

I was chatting with a friend and we couldn't decide on an answer to the following question:

If you cast a spell, can you respond to it with an instant or ability or will it resolve before you can?

Example:

Player A Casts Impulse
Player B Passes Priority
Player A Resolves Impulse? OR Player A Casts Brainstorm in response?

[rvs]

That's not exactly how it works:

Player A Plays Impulse.
Player A Passes Priority.
Player B Passes Priority.
Impulse Resolves. There's no window there for player A to do anything.

To create the intended situation, this is what happens:
Player A plays Impulse
Player A plays Brainstorm
Player A passes priority
Player B passes priority
Brainstorm Resolves
Impulse Resolves

Basicly, you are probably mistaken by a common (and perfectly fine) shortcut that you don't explicity pass priority after you play 1 spell, since often you aren't going to play another before passing priority (Ofcourse, the 2nd spell has to be instant, since you're essentially responding to your own spell). It's funny how I learned about it when I started playing Long with their LED's and stuff, where it's actually important you know about this shit.

Also, what seems to be wrong in your assumption is that you guys don't realise there is an explicit priority passing from the player playing the spell after he puts it on the stack. Shortcuts or no, this is what happens.
Btw, above examples are all assuming your opponent has no play.

[Ephraim]

I'd argue it's not a "perfectly fine" shortcut. I've found that people who learned about the stack while using that shortcut develop the mentality that after I cast a spell they have the first opportunity to respond. It seldom significantly affects the outcome of the stacking, but it's been irritating in trying to explain to people why they 1) don't have the priority to Unsummon my Mesmeric Fiend before I have the opportunity to sacrifice it and 2) why I could still sacrifice it even if they did have priority.

[Jebus]

MoreFling's example didn't note this, but I thought it was worth mentioning.

You also get an opportunity to play spells and abilities after each object on the stack resolves.  So the example would actually look like.

Player A plays Impulse
Player A plays Brainstorm
Player A passes priority
Player B passes priority
Brainstorm Resolves
Player A passes priority
Player B passes priority
Impulse Resolves

[The Grim Reaper]

Thank you all for clearing this up

[rvs]

You're right Jebus. I just figured that was logical with my explenation about it though. I guess I shortcutted there myself.

[rvs]

I'd argue it's not a "perfectly fine" shortcut. I've found that people who learned about the stack while using that shortcut develop the mentality that after I cast a spell they have the first opportunity to respond. It seldom significantly affects the outcome of the stacking, but it's been irritating in trying to explain to people why they 1) don't have the priority to Unsummon my Mesmeric Fiend before I have the opportunity to sacrifice it and 2) why I could still sacrifice it even if they did have priority.

Your 2) is flawed. That doesn't make sense.

[DEA]

it actually does
he can sacrifice it in response to them targetting the mersmeric fiend provided he has a sac outlet at instant speed

[Jebus]

What MoreFling is saying is that you can't do anything when you don't have priority.

The statement "...I could still sacrifice it even if they did have priority." does not make sense.

You will probably get priority eventually though.

[DEA]

which is the general gist of what ephraim was trying to say
inter linea  

[Jebus]

which is the general gist of what ephraim was trying to say
inter linea  

Not a "perfectly fine" shortcut as far as I'm concerned.

[Matt]

Perhaps Ephraim meant "even if I'm not the active player."

[Ephraim]

I did not mean "even if I am not the active player." I admit that I was unclear. I meant that even if he had priority to cast his Unsummon, eventually, before it resolved, I would get priority to sacrifice the Mesmeric Fiend.

Let's not even go into the fact that I'd also have to explain why his Unsummon would yield the same net effect from the Mesmeric Fiend, since he can't possibly stack the Unsummon at a time when it would resolve after the CIP effect, unless I don't end up sacrificing it and let the CIP effect resolve normally.

[virtual]

it actually does
he can sacrifice it in response to them targetting the mersmeric fiend provided he has a sac outlet at instant speed

Actually, he doesn't even need a sac outlet at instant speed.  After the whole stack resolves (fiend being the last thing on the stack), he gets priority again for anything, sorcery, or instant.  So he could cabal therapy before they got a chance to unsummon.  

I actually had this come up, guy casts his mox emerald (I have a gorilla shaman out).  He can tinker it before I can eat it.  Teh suck.  Teh Tehc.  

Please correct me if I'm wrong.

[Jebus]

it actually does
he can sacrifice it in response to them targetting the mersmeric fiend provided he has a sac outlet at instant speed

Actually, he doesn't even need a sac outlet at instant speed.  After the whole stack resolves (fiend being the last thing on the stack), he gets priority again for anything, sorcery, or instant.  So he could cabal therapy before they got a chance to unsummon.  

I actually had this come up, guy casts his mox emerald (I have a gorilla shaman out).  He can tinker it before I can eat it.  Teh suck.  Teh Tehc.  

Please correct me if I'm wrong.

Fiend has a comes into play ability that goes on the stack when it resolves, so your opponent will get a chance to respond to that.

The whole point of this is to sac the Fiend at instant speed to do "nightmare tricks".

[Ephraim]

It has to be at instant speed - I'm trying to respond to the Fiend's own Comes-into-Play effect by sacrificing it, so the Leaves-Play effect will resolve first. Otherwise, sacrificing the Mesmeric Fiend just gives my opponent the removed card back.

[virtual]

After you cast the fiend, could you cast an instant, and have it stack below the fiend's triggered ability?  Is there a window there for you to cast instants, or can you only stack on top of the triggered ability.

-Virtual

[Jaapmans]

After you cast the fiend, could you cast an instant, and have it stack below the fiend's triggered ability?  Is there a window there for you to cast instants, or can you only stack on top of the triggered ability.

-Virtual

if there are any triggered abilities waiting, they will go on the stack as soon as one of the players gets priority. Only after these abilities have gone on the stack the player that received priority can cast spells and play activated abilities etc.

So no, there is no window between receiving priority and the triggered ability going on the stack.

Jaap