So, at level 9, warlocks seem to learn their last Pact Magic slot. At levels 11, 13, 15, & 17, they learn their 4 Mystic Arcanum spells (levels 6, 7, 8, & 9, respectively).

But at level 19, there's that pesky 15th "Spell Known". What can one choose with that spell? Do you add a second level 5 spell at this time? That seems like an odd choice, but you clearly can't choose a second level 9 Mystic Arcanum spell. That language is pretty clear.

From level 9 on, current spell progression is: 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15.

Shouldn't it be: 10, 11, 12, 12, 13, 13, 14, 14, 15, 15, 15, 15?

This would provide 2 5th level "Spells Known" instead of just one and eliminate the issue of what to do with that unaccounted for level 19 spell. 

Maybe even add a 5th Spell Slot at 19?

What do you think?

Prepared spells and slots are not the same. At level 19 you have 4 spell slots of Level 5. However, you can have prepared  think memorized) a total of 15 spells of levels 1-5.

There's "Pact Magic" and there's "Mystic Arcanum". Pact Magic covers spell levels 1 thru 5. The column on the chart that lists the number of prepared spells you're allowed at each level refers strictly to your Pact Magic. So at level 9 you can have 10 Pact Magic spells prepared, of which you can cast 2 per short or long rest. At level 11 you can have 11 Pact Magic spells prepared, of which you can cast 3 per short or long rest. Separate and apart from that, you also have 1 Mystic Arcanum 6th level spell that you can cast once per day without using a spell slot. So at level 19 you can have 15 spells prepared of spell levels 1 thru 5, of which you can cast 4 per short or long rest. In addition to that you can cast your 6th level spell once per day, your 7th level spell once per day, your 8th level spell once per day, and your 9th level spell once per day.

Quote from Kennedict_Coggins >>

So, at level 9, warlocks seem to learn their last Pact Magic slot. At levels 11, 13, 15, & 17, they learn their 4 Mystic Arcanum spells (levels 6, 7, 8, & 9, respectively).

But at level 19, there's that pesky 15th "Spell Known". What can one choose with that spell? Do you add a second level 5 spell at this time? That seems like an odd choice, but you clearly can't choose a second level 9 Mystic Arcanum spell. That language is pretty clear.

From level 9 on, current spell progression is: 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15.

Shouldn't it be: 10, 11, 12, 12, 13, 13, 14, 14, 15, 15, 15, 15?

This would provide 2 5th level "Spells Known" instead of just one and eliminate the issue of what to do with that unaccounted for level 19 spell. 

Maybe even add a 5th Spell Slot at 19?

What do you think?

 The spells prepared on the chart don't have anything to do with mystic arcanum.

Warlocks continue preparing spells of 1st thru 5th level and pact slots are used to cast those spells.

They have massively better Invocations, Class Features, and Subclasses. So yeah, they feel a LOT better now.

Of course, this relies on your DM actually using Short Rests, but https://vlc****/ that's also a focus of the 2024 rules, giving every class a reason to make a Short Rest.

Good gravy... So, a level 20 Warlock would have the following:

15 prepared spells (of levels 1-5),

4 Mystic Arcanum spells (1 each of 6th, 7th, 8th, & 9th),

& 10 (or more) Subclass spells,

Plus any spells gained from Invocations, Species, Background, & feats,

4 Spell Slots (for those 15 Prepared Spells, and the 10+ subclass spells) regained on a Short Rest,

1 daily cast of each Mystic Arcanum spell,

At Will casting of most Invocation spells,

And, typically, 1 free daily casting of Species, Background, & Feat spells.

Not bad at all!

It's much better than I had initially understood. 😃

And once per day they can regain all 4 slots by taking 1 minute to use their Magical Cunning feature. 

Regardless, it's gonna feel a bit tight compared to full casters, but especially with subclass spells being always known now, their flexibility is a lot better.

Quote from The_Ace_of_Rogues >>

And once per day they can regain all 4 slots by taking 1 minute to use their Magical Cunning feature. 

Regardless, it's gonna feel a bit tight compared to full casters, but especially with subclass spells being always known now, their flexibility is a lot better.

They also reload patron slots when someone casts prayer of healing (or catnap if it's allowed, or both) if someone has it.  At 20th level it's likely someone will have it even if it's on a scroll.  It's actually pretty easy for a high level warlock to cast over 20 spells in an adventuring day.  Their only restriction is they can't cast more than 4 pact slots in an encounter.

In a day it goes something like this...

The first column represent how many spells it would take to go through the spell slots / pact slots + mystic arcanum and other spells the base class provides.  The other columns indicate casting a spell or taking an alternative action.  This gives us a rough visual on the level of those spells and how many spells each is casting before running out of gas.

This is assuming 2 short rests regardless of how those short rests are obtained.  No feats or subclasses are being considered in that chart.  This is at 20th level.

Other notes...

Bard:  Bards don't have ways to recover spell slots like other full spellcasters and the assumption is that the bard did not use spell slots to recover bardic inspiration uses.  Bards don't have the lasting power we see with sorcerers through font of magic, warlocks through pact magic and SLA's, or wizards through various means.  While bards do have access to higher level spells I don't think they have the lasting power to match the lower spell spells artificers have because of the spells storing device.

Cleric:  Clerics can use divine intervention to replicate a 5th level spell once per day and this is included.  The better version is not included because of the time to recover the ability.

Druid:  At 20th level there's nothing stopping a druid from immediately creating an 8th level spell slot by converting 4 wild shape uses  because they also recover a use of wild shape any time they roll initiative and have none so there isn't a significant reason not to make that assumption.  They can also recover a 1st level slot using a wild shape use.  I would note that the 8th level slot (or lower as the case may be) is only there at 20th level while the 1st level slot is easy to recover.

Sorcerer:  I'm assuming the sorcerer creates two 5th level slots to remain competitive, and uses the rest of the sorcery points on metamagic.  It's possible to vary this significantly and I went that way to help compare to warlocks.

Warlock:  The free casting of contact other plane is included in the list.  It's worth noting that with "cantrip/SLA" the SLA's available through invocations range in from 1st through 4th level spells.  Warlocks lose out a bit in the high end of spells but they have plenty in the mid range and low end to keep up with other spellcasters, which is where I'm going with this.  ;-)

Wizard:  The wizard is using arcane recovery to recover two 5th level spell slots for similar reasons as the sorcerer example.  In the wizard's case there's also a 1st and 2nd level SLA available through spell mastery, and 2 free castings of 3rd level signature spells that recover on a short rest.  Wizards tend to dominate the high level spells based on their spell list and mechanics adding spells to it; and they also tend to dominate the low level spells because of arcane recovery, ritual adept, spell mastery, and a signature spells at this level.

It's worth noting that many of those 3rd level spells being cast are only available at 20th level, and spell mastery is a very high level ability.  Wizards are still pretty good with arcane recovery and ritual adept outside of that point.

Artificer (UA):  There are a few important considerations here.  The first is the obvious benefit of the spell storing item holding ten 3rd level spells.  The other important consideration is the magic item tinker ability.  I didn't use draining an item to regain a spell slot because that seems like an exception to typical play to me.  I did, however, assume an item like a wand of fireballs is a reasonable expectation at that level either by finding or crafting one, and that allows for leveraging spell slots to recharge items.  With the wand of fireballs, for example, an artificer can use a 2nd level slot to add 2 charges and use those 2 charges to cast a 4th level fireball from the wand and use 1st level slots to recharge the wand and cast 3rd level fireballs.  There are nuances to doing this but ultimately artificers can use the magic item tinker ability to use lower level slots and to cast higher level spells from items than those slots would.  Between the spell storing item and recharging magic items with magic item tinker an artificer is fairly well stacked with the bottom of midrange (I define midrange as 3rd-5th level spells) spells.

For illustrative purposes that chart uses three 2nd level spell slots to cast three 4th level fireballs from a wand, and four 1st level slots to cast four 3rd level fireballs from the same wand.  This is also something with a lot of room for variations.

Paladin:  The chart includes the free castings of divine smite and find steed.

Ranger:  The chart includes the free castings of hunter's mark.

Arcane Trickster and Eldritch Knight:  There aren't really any assumptions to make with these options.  They're the only two subclasses list and I included them because they're prominent enough options that they should be included in the comparison.

Keeping it on topic... We could take away one short rest and the wizard loses two 3rd level spells cast.  The warlock loses four 6th level spells but that's still comparable to other full spellcasters because those other casters in into their low level sell slots that warlocks can match and exceed with SLA's.  I don't think warlocks really fall behind.

 EDIT:  That table formatting came out terrible.  Sorry.  Hope it's still understandable.