Things You Didn’t Know About D&D: Multiclass Spellcasting

I am constantly seeing confusion about how multiclassed spellcasting works, and I am constantly frustrated to see people who have no idea how it works offering up incorrect garbage as though it is incontrovertible fact. It’s about high time this was properly elaborated. 

So you have decided to multiclass. Congratulations, you have entered a whole new dimension of customizing your character, one with a long and storied history dating back many editions. Oh, and I see you’ve chosen to branch into a second spellcasting class. You’re in for some fun times, for sure! Unfortunately, with more customization comes more rules, and some of the most complex rules are those surrounding how to handle multiclass spellcasting. In fact, it’s one of the most frequently misunderstood systems in the game, one that even veteran players get this wrong. Fortunately, you’ve come to the right place for help. Here are the points to remember.

Spell Slots are Calculated and Shared Between All Spellcasting Classes

The Multiclass Spellcaster table on page 165 of the Player’s Handbook gives you the total number of spell slots you have. The number is based on your total spellcaster level, which is calculated using the following steps taken from page 164:

  • Add together all your levels in the bard, cleric, druid, sorcerer, and wizard classes;
  • Add half your levels (rounded down) in the paladin and ranger classes; and
  • Add one third of your levels (rounded down) in the eldritch knight (fighter) or arcane trickster (rogue) classes

For example, if you are a 5th-level eldritch knight, a 7th-level arcane trickster, and a 2nd-level wizard, you count as a 5th-level multiclass spellcaster. If you are a 5th-level paladin and a 11th-level cleric, you count as a 13th-level multiclass spellcaster. If you are a 16th-level wizard and a 1st-level cleric, you count as a 17th-level multiclass spellcaster.

You Prepare Spells Based On Each Class

This is the point where most people go wrong. According to page 164, when you are preparing spells, you treat each class separately, completely ignoring the multiclass spellcasting section entirely. If you have one level of druid, it doesn’t matter how many other spellcasting levels you have, you prepare druid spells as though you were a 1st-level druid.

Each Spellcasting Class Has Its Own Spellcasting Ability

If you are a 1st-level wizard and a 1st-level cleric, you use Intelligence as your spellcasting ability for wizard spells and Wisdom as your spellcasting ability for cleric spells, as though you were a single-class spellcaster for each of those classes. You do not get to cast your wizard spells using your Wisdom as the spellcasting ability.

You Will Probably Get Higher Level Spell Slots Than You Have Spells

Say that you are a 4th-level druid who gains a level in cleric. According to the Multiclass Spellcaster table, you have access to 3rd-level spell slots. However, the Druid table on page 65 of the Player’s Handbook shows that a 4th-level druid does not have 3rd-level spell slots. Therefore, to prepare a spell like call lightning, the character would have to take another level of druid.

This does not mean that such a character cannot use their 3rd-level spell slot. Once they have prepared their spells, they can cast a prepared spell at a higher level following all the normal rules found on page 201 of the Player’s Handbook. For example, if they prepared the 1st-level druid spell cure wounds, they could cast it using their 3rd-level spell slot.

What’s the Deal with Warlocks?

Instead of other spellcasting classes, which have the Spellcasting class feature, warlocks have something called Pact Magic. You do not add your warlock level to your other levels when determining how many spell slots you have on the Multiclass Spellcaster table. Instead, the spell slots granted by Pact Magic are in addition to the ones granted by Spellcasting. What’s really cool about this is that you can use spell slots granted by Pact Magic to cast spells from another spellcasting class, and vice versa. Also, given that all of their spell slots are of the same level, and that level gets higher as you advance in warlock levels, taking some levels as a warlock can be a very appealing option for some multiclass characters.

Don’t Trust Everything You Read Online

One of the most wonderful things about this day and age is that people can communicate about confusing things quite easily. Of course, this also means that many people who think they know what they’re talking about get to put incorrect information into the public knowledge. For example, Mythcreants put out an article a while back claiming that a 17th-level wizard/1st-level cleric multiclassed spellcaster could prepare 9th-level cleric spells. Their fallacious explanation went as follows:

Page 164 of the mutliclassing rules states: “You determine what spells you know and can prepare for each class individually, as if you were a single classed member of that class.”

It then gives an example of wizard/ranger, neither of which prepares spells like a cleric does.

Back on page 54 of the cleric class rules, after explaining how you choose a list of cleric spells to be able to cast, the book reads “the spells must be of a level for which you have spell slots.”

Note that it does not say “cleric spell slots.”

Then back on page 164: “You determine your available spell slots by adding together all your levels of bard, cleric, druid, sorcerer, and wizard…”

So when you’re preparing your spells as a first level cleric, you can pick spells of any level for which you have slots, which in this case will be levels 1-9 because when you combine your class levels together, those are the slots available to you for casting.

Now, this honestly frustrates me. It frustrates me because the folks over at Mythcreants have demonstrated that they are clearly capable of reading, and yet it seems to me that they have consciously gone out of their way to display the least degree of reading comprehension imaginable. In their attempt to justify such egregious, shameful rule-breaking, they have completely and utterly disregarded the very first words in the Spells Known and Prepared subsection of the multiclassed spellcasting write-up, which I will quote again for emphasis:

You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class.

The fact that they themselves quoted this makes it even worse, but I will endeavour to move on before I give myself an aneurysm.

Remember the example above with the 4th-level druid who had access to a 3rd-level spell slot due to their multiclassing choice, but couldn’t prepare 3rd-level druid spells? The exact same rules apply here. Just as the multiclassed druid counted only as a druid for the purpose of preparing druid spells, so does the cleric in the example the folks at Mythcreants have conceived. In other words: according to the rules on page 57 of the Player’s Handbook, that character can only prepare a number of 1st-level cleric spells equal to their Wisdom modifier + their cleric level. If they have a Wisdom score of 16, that means they can prepare four 1st-level cleric spells. I’ll say again: 1st-level cleric spells.

Now, once those spells have been prepared, they can be cast using any available spell slot, just like the druid in our earlier example could do. Given that the character has 17 levels of wizard, that means that the 1st-level cleric spell could be cast using a 9th-level spell slot. This is the only time the previously-accumulated higher-level spell slots have any bearing whatsoever on the way that the character casts their cleric spells.

So, unfortunately for those who subscribe to Mythcreant University’s Power Gaming 101 philosophy, their thesis is definitively incorrect. This is why it is important to read the rules carefully, and why you should never trust what you see on the internet (unless you see it here first, or it comes directly from the Mouth of God via Sage Advice).

Some sources from the designers which support my explanations:

  1. Learning 3rd-level spells with a 2nd-level wizard.
  2. Copying vs. learning higher-level spells. (Note: the Player’s Handbook Errata later restricted copying spells into a wizard spellbook to spells that the wizard could prepare.)
  3. And last but not least, a Sage Advice that definitively supports my rebuttal to the folks at Mythcreants, who really need to revise or remove their misleading article.

8 thoughts on “Things You Didn’t Know About D&D: Multiclass Spellcasting”

  1. Hey, Oren from Mythcreants here. Thanks for posting a link to us!

    While I wouldn’t rate anything here as 1,000,000,000% wrong (though I’m flattered you thought my article rated a billion on any metric), I do think you’re reading Rules as Intended rather than Rules as Written when it comes to the Cleric multiclass spellcasting.

    The trick comes in the way the Cleric learns spells. That is, they don’t. Per page 58, Clerics effectively know their entire spell list, and are only limited by the spell slots their have available. Druids work this way too. Rangers and Wizards, on the other hand, have a limited number of known spells that they can choose from.

    Per page 164, you determine which spells you know and prepare for each class individually. So when my Wizard 17/Cleric 1 is preparing spells as first level Cleric, he knows every Cleric spell on the list. He need only expend spells lots of the appropriate level to cast them.

    Since my character does not have Wizard Slots and Cleric Slots, only their total Spell Slots from their combined class levels, they can prepare any spell from the Cleric list as a first level Cleric.

    I’m certain this isn’t what the 5E designers intended, but it is what they wrote. I’m not suggesting anyone should run 5E this way, god knows I didn’t, I’m only looking at what the rules actually allow, and in this case they allow for an overpowered combination.

    A GM is always free to say no, but it would have been better for the rules not to allow such a combo in the first place. Experienced GMs know not to allow this, but a newbie GM who isn’t clued into our conversation might not know any better.

    1. Thanks for replying to our comment!

      I would like to say that I understand your position on the matter of preparing spells, but the rules are really quite clear: you prepare spells for that class as though you were a single-class spellcaster. That means that if you are a 1st-level cleric, you can only prepare 1st-level cleric spells. Now, you can point to the general wording in the Spellcasting class feature perhaps giving you a free pass, but in doing so you would be neglecting the specific restrictions described in the Multiclass Spellcasting section. And, as is deliberately specified on page 7 of the Player’s Handbook, specific beats general.

      I’m sorry, but you are conclusively wrong that there is a RAW way to cast 9th-level cleric spells as a 1st-level cleric. If you want to be a GM who says that’s acceptable at your table, that’s your prerogative to suspend the rules. But, no, the rules do not allow for it; you are simply misreading them.


      – the Archmage

  2. In your EK 5/AT 7/W2 example you should be a 6th level caster not 5th.

    The rules state, “one third your fighter or rogue levels”. The lack of the word ‘each’ heavily implies a third of your combined fighter and rogue levels. You divide after adding, otherwise you’re just doubling the rounding error when it’s not required.

    Thus 2 + (7 + 5)/3 = 2 + 12/3 = 6

    As for the other issue, it’s clear in the examples given in the multiclassing section of the PHB that spells known are determined by the individual level of each class. An example in the rules is the very definition of specific when it comes to the specific vs general rule.

    1. Thank you for your comment!

      Actually, 5th-level spellcaster is correct. Your math seems to have been jumbled.

      To clarify, a 5th-level Eldritch Knight counts as a 1st-level spellcaster (5/3, round down), and a 7th-level Arcane Trickster is a 2nd-level spellcaster (7/3, round down). That makes 3 spellcasting levels, plus the extra two from being a 2nd-level wizard makes 5.

      As to your point about EK and AT levels not stacking, I’m reasonably certain that this is not the intention of the rules, and it’s certainly not how I would run it at my table. Nonetheless, having found no Sage Advice that would confirm or refute either position, I have reached out to Mike Mearls and Jeremy Crawford on Twitter to clarify. It may be that you are correct. We shall see.

  3. Hey,

    In my campaign, I’m multiclassing an arcane archer fighter and horizon walker ranger (both from xanathar’s guide). How does my spells work then. I’m currently level 13 (8F/5R). Do I follow the multiclass chart or do I just follow the ranger’s chart for spell slots, since my arcane archer has no spells.

    1. Thanks for commenting!

      Because the arcane archer does not have the Spellcasting class feature, the process outlined above for determining your “spellcaster level” does not apply. You simply follow the ranger’s chart for spell slots.

      – the Archmage

  4. So I am a Lv9 Rogue (arcane trickster) about to Multi-class into a level of Cleric for… reasons. (One word: Strahd).

    Anyway, I’ve been staring at the book for hours, but I’m still extremely confused. Now admittedly I’m probably overthinking this, but it worries me that I’m LOSING slots instead of gaining them?

    Performing the math, (9/3) +1 indicates that for multi-classing purposes, I’d be a Level 4 caster, right? Using the chart in the book, that seems to indicate that I get 4-1st level slots, and 3-2nd level slots. Yet, my Lv9 arcane trickster rogue has 6-1st level slots, 4-2nd level slots, and 2-3rd level slots.

    Basically I’m looking for confirmation that I get all the slots listed above instead of just the multi-class slots.

    As in: 6-1st level slots, 4-2nd level slots, and 2-3rd level slots for Rogue Spells and 4-1st level slots, and 3-2nd level slots for Cleric Spells. Is that correct? If not, it appears I’d be LOSING a significant amount of slots to multi-class… so… Can anyone help?

    1. Hi K8AN,

      Thanks for commenting!

      When you gain a second spellcasting class, you use the Multiclass Spellcaster: Spell Slots per Spell Level table on page 165 of the Player’s Handbook. You do not get those slots in addition to other spell slots you have.

      I believe that your confusion arises out of misreading the Arcane Trickster Spellcasting table. In fact, you currently have four 1st-level spell slots (not 6), two 2nd-level spells (not 4), and no 3rd-level spells. You know 6 spells in total (the number which you have mistaken for your number of 1st-level spell slots). When you correct for the misread, you will see that, when you take your next level in cleric, you will actually gain one additional 2nd-level spell slot (using the 4th-level line from the Multiclass Spellcaster table), rather than losing spell slots.

      Hopefully this clears things up for you.

      – the Archmage

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