Sorcerer5/Warlock5/fighter2

[Jpeichorn]

Could my character cast a quicken eldritch blast, a eldritch blast, use the fighter action surge, and do the same thing again? using the sorcerer's quicken spell?

[LordEntrails]

Not per my understanding. Or not exactly as you are putting it.

Quicken spell turns a 1 Action spell into a 1 Bonus Action spell. So doing that you have now used your bonus action. But, a warlocks' eldritch blast is a cantrip and I don't know if you can raise the level of a cantrip. You would need to check on that since cantrips level up already with character level.

Action surge does allow a second action, so you can cast another spell * but you can't take a second bonus action so you can not cast another quicken spell. But not sure you need to quicken the Eldritch blast again.

*Note, the PHB has a rule that goes something like if you cast a spell that takes an action, you can only cast another spell in the same round if it is a cantrip that takes a bonus action.

So, you can take an action to cast any spell, then take an Action surge, but not to cast another levelled spell because the PHB rule. Though you can still them cast a quickened spell to make it a cantrip. So, two spells, one quickened and one not. Not sure the action surge actually buy you another spell.

But, as DM, I might allow it, after all, you will quickly be burning through your spell slots and daily powers.

[Dire Weasel]

1) Quicken eldritch blast, and cast it as a bonus action.
2) Use your action to cast eldritch blast.
3) Use your action surge action to cast eldritch blast.

That's 3 eldritch blasts.
Action surge does not give you another bonus action, just another action.

[LordEntrails]

1) Quicken eldritch blast, and cast it as a bonus action.
2) Use your action to cast eldritch blast.
3) Use your action surge action to cast eldritch blast.

That's 3 eldritch blasts.
Action surge does not give you another bonus action, just another action.
Except as I stated earlier, there is a rule in the PHB that forbids that.

Specifically from Chapter 10, "Casting a Spell > Casting Time > Bonus Action"
"You can't cast another spell during the same turn, except for a cantrip with a casting time of 1 action"

Some folks interpret it in a few different ways. There is a long and involved thread on ENWorld if you care to look it up. Includes quotes from Sage Advice and tweets from Jeremy Crawford.

My interpretation is that if you use an action and a action surge, you get 2 spells off, but then you can not cast anything as a bonus action. If you cast a cantrip as a bonus action, then you can cast one action spell. Either way, that's 2 spells, not 3.

[GavinRuneblade]

My interpretation is that if you use an action and a action surge, you get 2 spells off, but then you can not cast anything as a bonus action. If you cast a cantrip as a bonus action, then you can cast one action spell. Either way, that's 2 spells, not 3.
Per RAW and Sage Advice the arrow of causality is very specifically only one direction: towards actions, there are no limits on the bonus action. Nothing restricts casting cantrips. If you cast any spell with a bonus action (no rule or sage advice puts limits on the order you cast them) the only spell you can cast with an action is a cantrip with a casting time of 1 action. Eldritch Blast is a cantrip with a casting time of 1 action. So, 2 actions that are both cantrips with a casting time of 1 action still allows you to cast a spell with your bonus action.

Where the ENWorld argument goes off the rails is people wanting to cast more than 1 levelled spell or wanting to do bonus action cantrip and action non-cantrip or wanting to use their reaction to cast a spell on the same turn (not later in the round usually this is counterspelling counterspell). The only way to do that is action surge and no spell on bonus action.

[Jpeichorn]

Per PHB a 2nd lvl fighter can a action surge (no action) and gain an additional action and possible bonus action.

if u look in the PHB under sorcerer it talks of using twinned spell on a cantrip, plus cantrips are under the spell list so they are spells.

under multiclassing in PHB a sorcerer and warlock spells are interchangeable and eldritch blast is a cantrip so they don't use spell slots.

Per PHB if you cast a spell as a bonus action you can only following spell has to be a cantrip.

So here is how my round would go:
quicken eldritch blast (bonus action), eldritch blast (action), fighters action surge (no action, additional action and bonus action), eldritch blast (action), quicken eldritch blast (additional bonus action).

our group defines "...possible bonus action." in PHB, using it if the PC has one available.

granted u would burn through your sorcery points, and could only do it once per long rest, but I haven't seen anything in the PHB preventing it.

[Jpeichorn]

Just read some of the previous threads more thoroughly and I can understand why a DM might not allow a nother bonus spell, our group will have to talk about it make a house rule

[LordEntrails]

OP, what I would take away for you with this discussion is "Ask your DM". In the end, that's the only ruling that matters :)

[GavinRuneblade]

Per PHB a 2nd lvl fighter can a action surge (no action) and gain an additional action and possible bonus action.

if u look in the PHB under sorcerer it talks of using twinned spell on a cantrip, plus cantrips are under the spell list so they are spells.

under multiclassing in PHB a sorcerer and warlock spells are interchangeable and eldritch blast is a cantrip so they don't use spell slots.

Per PHB if you cast a spell as a bonus action you can only following spell has to be a cantrip.

So here is how my round would go:
quicken eldritch blast (bonus action), eldritch blast (action), fighters action surge (no action, additional action and bonus action), eldritch blast (action), quicken eldritch blast (additional bonus action).

our group defines "...possible bonus action." in PHB, using it if the PC has one available.

granted u would burn through your sorcery points, and could only do it once per long rest, but I haven't seen anything in the PHB preventing it.

https://www.sageadvice.eu/action-surge-bonus-action/
Quoting Sage Advice: "Action Surge refers to the fact that you might have a bonus action, not that you might have more than one. "
You still only get 4 spells. Now if you somehow manage to use the Samurai's ability to take a full extra turn, you could pull off 6. But that takes 18 levels of fighter. So you'd need the metamagic feat from Tasha's to do it.

[Radditz0012]

Here is what Jeremy Crawford Says on this Topic

https://twitter.com/jeremyecrawford/status/1151294046758825984?lang=en