Timing

[Estel2931]

I cast a {Goblin Dark-Dwellers}... My friend casts {Go for the Throat} in response to hus triggered ability. Would I be able to bring back {Spell Pierce} to counter that or what happens?

[Spencer Addington]

I cast a {Goblin Dark-Dwellers}... My friend casts {Go for the Throat} in response to hus triggered ability. Would I be able to bring back {Spell Pierce} to counter that or what happens?

Goblin enters
Trigger goes on the stack letting you pick which card to cast
Response to the trigger he goes for the throat

Your opponents spell will resolve before the triggered ability resolves, so the goblin dies before he give you the option to cast a thing for free.

[redwolv]

I cast a {Goblin Dark-Dwellers}... My friend casts {Go for the Throat} in response to hus triggered ability. Would I be able to bring back {Spell Pierce} to counter that or what happens?

Goblin enters
Trigger goes on the stack letting you pick which card to cast
Response to the trigger he goes for the throat

Your opponents spell will resolve before the triggered ability resolves, so the goblin dies before he give you the option to cast a thing for free.

Actually your half right, half wrong.

Tigger ability goes on the stack. You pick which card to be able to cast from the graveyard at that point.
He casts go for the throat.

His go for the throat kills your goblin. Reguardless which you picked for GDD even if you picked spellpeirce you can't cast it yet.

Now gdd's effect resolves. The selected spell can now be cast.

[Spencer Addington]

I cast a {Goblin Dark-Dwellers}... My friend casts {Go for the Throat} in response to hus triggered ability. Would I be able to bring back {Spell Pierce} to counter that or what happens?

Goblin enters
Trigger goes on the stack letting you pick which card to cast
Response to the trigger he goes for the throat

Your opponents spell will resolve before the triggered ability resolves, so the goblin dies before he give you the option to cast a thing for free.

Actually your half right, half wrong.

Tigger ability goes on the stack. You pick which card to be able to cast from the graveyard at that point.
He casts go for the throat.

His go for the throat kills your goblin. Reguardless which you picked for GDD even if you picked spellpeirce you can't cast it yet.

Now gdd's effect resolves. The selected spell can now be cast.

My wording was different than what I meant on the last thing. No matter what, unless they counter the triggered ability, you get the option to cast the spell you choose for free, provided there is a legal target if the spell targets anything. It's just your goblin dies before you get to cast it, since the trigger hasn't resolved.

[Estel2931]

Thank-you both

[griffin131]

Just wanted to emphasize what redwolv said - you target a spell in your GY when GDDs trigger goes on the stack, not when it resolves.