Can a warlock gain a 2nd familiar by multiclassing into wizard?

Question

Last time our Warlock friend leveled up, and as he did we called it a night. Today he came over to discuss options for multi-classing, as he feels the Warlock is somewhat limited in spells. The normal advice was of course to pick Sorcerer or Bard, since Charisma and all that. But he's hellbent on going with a Wizard.

The reasoning he gave us, was that he would have 2 Familiars. One from his Pact of the Chain, and then one from summoning it with a Wizard spell.
We tried to explain to him that the book says the following in the spell description:

You can’t have more than one familiar at a time. If you cast this spell while you already have a familiar, you instead cause it to adopt a new form.

As many players do when they get told no, he tried to give us reasons why that wasn't right.

1. It's a spell from a different class. If he has to use different spell slots and different spell levels when he's using different classes, he should also be able to have different effects instead of being forced to have the same one.

2. The book is written like that because it's not taking multi-classing into account in "spell tooltips".

3. (This one had me giggle) If he has the spell on 2 classes for his character, can't he at least combine the two to summon a bigger Familiar, like an Owlbear or something like that?

The question

1. I'm quite sure he just shouldn't be getting anything extra

2. casting the spell on the Wizard side of his character would just be a less efficient version of his Warlock one

What do the rules really say?

Answer 1

You answered it yourself. NO.

As you said, by RAW, casting Find Familiar will get rid of any previously existing Familiar and that is the end of that. It does not say it has to be from any particular class.

As far as "should I allow them to do it anyways?" I would still suggest no. Battles are only going to slow down with having extra creatures and one of the players is going to have triple the amount of things to do compared to the rest. This is without even considering any possible exploits that could come from this.

Making the familiar stronger also has it's own cons, as a "pet" that is comparable to other PC characters can seriously shift the balance of the game, especially for that character who only needed to be level 4 to play a "second character". If you take this route, it should not be something like an owlbear but another small utility outsider like the ones Warlock gets.

It would be a more compassionate case if not for the fact that Wizard can just pick different spells and maintain their full effectiveness. He's not "losing" anything with this multiclass.

If you still want to give him something, let him change his pact to something else or add some new options to the familiar list that aren't stronger than the unique ones he already gets.

Answer 2

The Pact of the Chain feature simply gives you the spell.

The text of the feature states,

You learn the find familiar spell and can cast it as a ritual.

This means that there's nothing special about the find familiar spell from the feature--it's identical to the spell that the wizard can learn. Thus, the spell is subject to the same limit of 1 familiar.

Addressing each point

1. Most spells are available to multiple classes, yet they have the same effect. Just because different classes use different slots and abilities doesn't mean that the spells themselves are different. A fireball is a fireball, whether it's from a bard or a wizard.

2. The statement on not having multiple familiars seems like an explicit reference to multi-classing. I'm not sure what "spell tooltips" are, but the wording of spells is (mostly) very carefully crafted, and there's no errata on this topic, even though there's errata on multiclassing overall.

3. Spending multiple spell slots (or higher level spell slots) to get stronger effects only works when it is explicitly laid out in the spell or in the class feature (Paladin smite novas, for example). Generally, one has to use a higher level spell slot to boost the effect, not multiple slots of the same level. Conjure Elemental, for example, lets you summon stronger elementals when cast in a higher slot. If you really wanted to boost the power of a familiar, you could require casting it in a higher level spell slot instead, though I imagine that this would be very difficult to balance.

Other comments

You say that using the spell on the Wizard class would be "less efficient," but consider that the warlock version is a pact boon, with pretty large opportunity costs. It's arguably less costly for the wizard to learn the find familiar spell than it is for the warlock.