How exactly do spells benefit from procs?

[Deleted]

What I mean is:

-Does a spell get the proc's benefit it the proc is up when starting the cast

-Or does the proc still have to be up when the projectile leaves your character's body?

Say I was a Destruction Lock and my Chaos Bolt takes exactly 3 seconds to cast, is it enough to start casting Chaos Bolt when there is 1 second left on the proc (say, A trinket proc like Expanded Mind from Immerseus Trinket) or do I need to start casting when there are over 3 seconds left of the proc?

[Larynx]

Channels and DoTs snap shot as they are cast. Cast times snap shot after they are cast (either when they leave your hand or when the damage appears, I believe the first is more likely). Some spells are not consistent with these rules.

[Toastiekins]

Larynx is correct. In the case of Chaos Bolt if you started a cast at 1s left of your proc you would not benefit as the Chaos Bolt cast finished after the proc had faded. If you have ever tried to use the Black Blood trinket (while tracking the proc of course) while destruction you would be painfully aware of this mechanic.

[Deleted]

Larynx is correct. In the case of Chaos Bolt if you started a cast at 1s left of your proc you would not benefit as the Chaos Bolt cast finished after the proc had faded. If you have ever tried to use the Black Blood trinket (while tracking the proc of course) while destruction you would be painfully aware of this mechanic.

This is EXACTLY why I am asking, because I got Black Blood yesterday as Destro and am making sure the best way to use it, at the moment I'm casting CB at 7 stacks. 8 with BL.

[Deleted]

What I mean is:

-Does a spell get the proc's benefit it the proc is up when starting the cast

-Or does the proc still have to be up when the projectile leaves your character's body?

Say I was a Destruction Lock and my Chaos Bolt takes exactly 3 seconds to cast, is it enough to start casting Chaos Bolt when there is 1 second left on the proc (say, A trinket proc like Expanded Mind from Immerseus Trinket) or do I need to start casting when there are over 3 seconds left of the proc?

your chaos bolts etc snapshot your stats the second the cast is finished.

[Toastiekins]

You can get two chaos bolts at high stacks. If you start a cast at 5 seconds you can get a second one out at 9/10 and maybe an immolate, depending on your haste.