I love the Warlock. But the 2 Spells per Short Rest for the most of his Career is frustrating, especially if you have a Campaign where Short Rests are not much more common than long Rest (Overland Travel).
Then it just hit me .. why not swap out the Short Rest Slots to the typical Caster-Spellsslots. So for Example at 5th Level he would have 3 first Level, 3 2nd Level and 2 3rd Level Slots which resets with a long rest .. instead of 2 3rd Level Slots which resets with a short Rest.
Cantrips and Spells Known would not be affected.
Is that reasonable or are there Problems with that?
The idea is interesting, certainly doable, with some additional adjustments.
IIRC, the Warlock gets almost the same (with slight delay) the same amount of spells known as the Sorcerer. The Wizard gets more than double that amount, plus the ability to buy more in exchange for gold. In terms of cantrip known, the Sorcerer knows one more than the Wizard who knows one more than the Warlock.
However, when you look at the special abilities (let's consider capstone abilities a bit separately since they are seldom reached):
- Wizard gets Arcane Recovery (more spell slots), and rituals (equivalent to even more spell slots); two huge capstone abilities that equate to... wait for it... even more spell slots! (and yet some people still think that the Sorcerer casts more spells/day than a Wizard as in 3e)
- Sorcerer gets sorcery points (about as valuable as the Wizard's Arcane Recovery in terms of more slots, but faster to use), 4 metamagic (unfortunately competing for the same sorcery points), and a mediocre 20% sorcery points refresh per short rest as capstone ability
- Warlock gets the pact boon, 8 invocations, and a mediocre slots refresh almost-free per day ("almost" because it still takes 1 minute, making it useless in combat)
I think some of the invocations are pretty powerful, so
perhaps all you need is decrease the number of invocations gained to e.g. 5-6.
You also need to update the "Eldritch Master" capstone ability because obviously you shouldn't allow it to regain ALL the spell slots after you've changed them to daily! Notice that the original "Eldritch Master" feature applies to the
regular 4 slots that the Warlock regains with a short rest but
not to the uses of Mystic Arcanum, so it's basically a refresh of only lower-level spells. You might want to take that into account when adapting "Eldritch Master" to the new Warlock.