D&D 5E Multiclass Spell Slot Question

[professorDM]

I'm curious how the Warlock's Pact Magic combines with other casting classes.

Let's say I have a 4th level Warlock/2nd level Sorcerer. As I understand the PHB's rules on spellcasters, I would be a 6th level caster with a 4/3/3 slot spread. Since I'm a 4th level WL, I'd know five WL spells; and since I'm a 2nd level Sorc, I'd know three Sorc spells. So I can cast those seven known (1st and 2nd level) spells according to that 4/3/3 slot spread? What's more, I'm also be able to regain two 3rd level slots on a short rest, via the Pact Magic feature?

This is awfully nice, considering a comparable 6th level Warlock would only have two 3rd level spell slots (both of which recharge on a short rest). Not only do I gain four 1st, three 2nd, and one additional 3rd level slot, I also still have my Pact Magic regeneration.

This is quite the multiclassing combo!

I don't think this breaks the game, but I'm curious as to whether or not this is the way the Warlock's abilities are meant to mix with other casting abilities. If so, Sorcerer/Warlock seems like it's easily one of the most powerful combos in the game---even more deadly as I combine Darkness and Devil's Sight (to attack with Advantage and be attacked with Disadvantage) and begin Twinning, Quickening, and Empowering the (fire) spells to which I am Elementally Affined. All this with an Imp or Pixie familiar and the glory of Agonizing Eldritch Blasts to fall back on.

 

[Actoba]

You only use the multiclass spell slot table when you have more than one class with the "Spellcasting" feature. Warlock does not have this.

So in your example you have warlock slots for whatever a lvl 4 warlock gets, and the slots you get from the lvl 2 sorceror spellcasting feature....plus all the spells that you know according to each class.

You can then use any slot (warlock or normal) to cast any spell you know with the warlock slots recharging on a short rest as normal, and the sorc ones on a long rest as normal. If you multiclass again into another class with spellcasting (like wizard for example), then you would use the multiclass spell slot table for your combined wizard and sorc levels, but your warlock slots would still scale separately and only with your warlock level