What is the maximum number of known spells (that can be cast with spell slots and use Charisma) a character can have?

Question

I often find it frustrating how few spells sorcerers have. This has led me to trying to increase the number of spells they have with a few multiclassing dips. I was then inspired to ask this question:

What is the maximum number of spells known a character can have?

I want this to be achieved primarily through multiclassing, so there are a few restrictions:

• The spells must be cast using Charisma as the spellcasting modifier, so multiclassing into Wizard or Druid doesn't help;
• I'm not including features you'd get through subclasses (i.e. Eyes of the Dark gives you darkness for free), since I want this solution to be a template I can stick any subclasses onto;
• A bard's Magical Secrets is allowed, since that's a base class feature, but Additional Magical Secrets is not, since that's Lore bard only;
• Feats are allowed, but Epic Boons and magic items are not;
• I'll allow Unearthed Arcana for this one, for example UA feats;
• The spells known must be cast via your spell slots that you have via your class features;
• I'll allow the number of spells a paladin can prepare to count as spells known for the purposes of this question, even though they actually know their entire spell list;
• Polymorphing into something else that can cast spells is not allowed;
• Assume a level 20 character, and whatever ability scores are necessary (although I imagine that'll just be Charisma 20);
• Also note that this question has nothing to do with the number of spell slots, only spells known.

Answer 1

You can get up to 38 spells under these conditions

In your own answer you already found 3 feats that provide extra spells known with charisma, for a total of 5 spells and they are Magic Initiate (from the PHB), Fey Touched and Shadow Touched (from Tasha's Cauldron of Everything²). Other feats that grant extra spells known with charisma are Telepathic (also from Tasha's) and Gift of the Metallic Dragon from the Draconic Options UA (1 spell each). This is gives us a total of 7 spells from 5 feats.

Focusing on spells from classes, though, we should note the following for each of the four charisma spellcasters:

• Bards have at most 4 more spells known than their level
• Warlocks have at most 1 more spell known than their level
• Sorcerers have at most 1 more spell known than their level
• Paladins (assuming 20 charisma) can prepare at most 5 more spells than their level

Given this, it would be optimal to have each of these classes at one such level. The more limiting ones seem to be bards and paladins. Bards having 4 spells known over their level only at levels 10, 14 and 18, and paladins managing to get 5 spells prepared over their level at levels 3, 4, 5 and 6. Fortunately, both sorcerers and warlocks are already optimal at level 1 which allows to simply take:

• Bard 14 for 18 spells known
• Paladin 4 for 9 spells prepared (5 from charisma, 2 from half level and 2 Oath Spells¹)
• Warlock 1 for 2 spells known
• Sorcerer 1 for 2 spells known

For a total of 31 spells, which with the 7 from the feats totals 38. This allows spells up to level 7 to be possible and since we are getting a bunch of bard magical secrets, some of them can even be from any class. We also get 12 cantrips (4 Bard, 4 Sorcerer, 2 Warlock, 2 Magic Initiate)

Regarding ability scores, we get 3 ASI from Bard levels and 1 from Paladin but we need to take 5 feats. With 3 feats granting +1 Charisma each, this also requires starting with 17 Charisma and 13 Strength (for paladin multiclassing).

The only way I found to make this work is by using the Custom Lineage option from Tasha's. This both allows starting with 17 Charisma (when using point buy or the standard array) as well as having one extra feat to make up for only getting 4 from classes. If this option is unavailable one feat must be given up making the total only 37 spells.

---

^{1. Although Oath Spells technically come from a subclass, all published paladin Oaths have exactly 2 oath spells at 3rd level so these should be available regardless of which one is chosen}

^{2. This answer has had the feats area heavily revised to account for later publishings (credit to user68fd for noticing these 2 feats were published on Tasha's)}

Answer 2

A total of 30 spells known that can be cast with spell slots using Charisma as the spellcasting ability

In my attempt to answer this, I've come up with the following:

• A character with no more than 18 in Charisma; race is irrelevant;
• Classes include Bard 7, Warlock 2, Sorcerer 11;
• Feats include Magic Initiate, Fey Touched and Shadow Touched (the latter two are from this Unearthed Arcana, pdf);

The build is:

• From 11 levels in Sorcerer, we get 12 spells known;
• From 7 levels in Bard, we get 10 spells known;
• From 2 levels in Warlock, we get 3 spell known;

That's a total of 25 so far.

• The Magic Initiate feat (assuming we pick one of the above classes) gives us an extra spell known, which according to Sage Advice (pages 3-4), can be cast with spell slots, so it counts and doesn't violate the question's restrictions;
• The Fey Touched feat (assuming we pick Charisma as our +1) gives us two extra spells known, one of which must be misty step and the other one must be from the divination or enchantment schools;
• The Shadow Touched feat (assuming we pick Charisma as our +1) gives us two extra spells known, one of which must be darkness and the other one must be from the illusion or necromancy schools;

That's a total of 30 spells known. Also note that, if we had Charisma 18, these last two feats would see us to Charisma 20.

It could be higher if we include Eldritch Invocations, but since we can't cast those with spell slots, they don't meet one of the question's requirements about being cast via spell slots, so we cannot include Armor of Shadows, Beast Speech, etc. Ritual casting via Pact of the Tome is also excluded for the same reason.

NB: I also get 13 cantrips out of this (6 from Sorcerer, 3 from Bard, 2 from Warlock, 2 from Magic Initiate)

---

Of course, this build restricts us to only having access to 6th level spells. If we sacrificed a few levels of bard for a few more levels in sorcerer, so now we are a Bard 1/Warlock 2/Sorcerer 17, we would only have 27 spells known (assuming the same feats as above), but with access to 9th level spells.