A thought-- spell-less Warlock?

[Dr. Cliché]

One minor thing I'd suggest (and this also applies to the normal Warlock) - I'd have them start with Eldritch Blast automatically.

It's a somewhat minor point, but it seems weird to have a class designed around an optional ability.

It looks like someone beat me to it, but if the Warlocks boons also became full class features that progressively grew in power with level I think that would provide plenty of material to work from.

A few Warlock only spells would probably need to be converted into Invocations for this concept to get off the ground, but I think it could work pretty well.

When I get some more time I'll toss together a mockup.

If you find the time I'd really like to see that.

[Nifft]

One minor thing I'd suggest (and this also applies to the normal Warlock) - I'd have them start with Eldritch Blast automatically.

It's a somewhat minor point, but it seems weird to have a class designed around an optional ability.

Eldritch Blast as a class feature removes a bunch of dipping abuse, too. It's a solid improvement from both a convenience and a balance perspective.

[krugaan]

Eldritch Blast as a class feature removes a bunch of dipping abuse, too. It's a solid improvement from both a convenience and a balance perspective.

Wait, how's that stop dipping?

[ATHATH]

You could try bringing back the sorting of invocations into different grades (Least, Lesser, Greater, and Dark) that are "unlocked" at different levels from 3.5e. It might be easier to balance than having every ability in the class be available at level 1, and it might make a good "substitute" for Mystic Arcanum. Plus, it'll probably line up well with the tiers of play that 5e's balance is built around.

[Nifft]

Wait, how's that stop dipping?

Who said anything would "stop dipping"?

[Grod_The_Giant]

Wait, how's that stop dipping?

I imagine it would be "get a second beam at WARLOCK level 5, 11, and 17," rather than character level.

You could try bringing back the sorting of invocations into different grades (Least, Lesser, Greater, and Dark) that are "unlocked" at different levels from 3.5e. It might be easier to balance than having every ability in the class be available at level 1, and it might make a good "substitute" for Mystic Arcanum. Plus, it'll probably line up well with the tiers of play that 5e's balance is built around.

There are already plenty of level-gated invocations, so that shouldn't be an issue.

[bid]

I imagine it would be "get a second beam at WARLOCK level 5, 11, and 17," rather than character level.

That should be part of agonizing blast, without the 4 * +5, eldritch blast is just another cantrip.

[krugaan]

That should be part of agonizing blast, without the 4 * +5, eldritch blast is just another cantrip.

This, pretty much. If anything, you could add extra invocations to add utility to EB (although I admit there are a ton already).

We already have extra damage, range, slow, push, pull... Did 4e already do shapes? Never played that edition.

Or even have something like smite be applicable to blast?

[Vogie]

I could see it.

They've actually released almost this precise idea... A metric ton of invocations, with at will, encounter, and daily powers. They just made it a bit too complicated and most people don't play it. It's called the Mystic.

You could, by the same token, using the Mystic Discipline skeleton as a collection of invocations would work with the warlock mechanical skeleton, even down to the "use spell slot" invocations (designed to introduce non-warlock spells that scale with level, such as Thief of Five Fates giving a scaling Bane... not that anyone would want that, as far as I can tell), but replacing it with a point system.

One of the reasons the Mystic's Psi Points got so unwieldy (going from 4 to... 71??) is because it was a LR based class. You replace that with a significantly smaller number of points due to the Warlock being a short-rest class, not unlike the Monk's Ki Points system.

[Rebonack]

If you find the time I'd really like to see that.

Ask and you shall receive.

Basic level outline would probably go something like-

1: Eldritch Patron, Eldritch Boon
2: Hex 1d6, Eldritch Invocations
3: Boon Feature
4: Ability Score Increase
5: Boon Feature, Hex 2d6
6: Patron Feature
7: Hex Feature
8: Ability Score Increase
9: Hex Feature
10: Patron Feature
11: Boon Feature, Hex 3d6
12: Ability Score Increase
13: Hex Feature
14: Patron Feature
15: Hex Feature
16: Ability Score Increase
17: Boon Feature, Hex 4d6
18: Hex Feature
19: Ability Score Increase
20: Patron Feature

So I figure Patron choice nets you two cantrips specific to that Patron, Eldritch Blast, and one cantrip of your choice from the Warlock list. Hex would be simplified a bit, triggers once per round when you damage something and inflicts the indicated amount of damage. That makes its damage a bit more reliable and allows it to be used with a wider selection of class features without any loss of effectiveness. The Hex Features would be a nice list of additional nasty effects to pick from (contagious hexes, area of effect hexes, hexes that trigger off allied damage, more painful hexes, hexes that gimp attack rolls or saves, ect). I'm pretty sure you would be able to get away with exactly the same number of Invocations granted at the same levels given that the Warlock is getting a heap of other features.

This is pretty bare bones, but it feels like a pretty solid starting point. With things like Hex and Boons getting their invocations rolled into major class features, that would save plenty of room for adding new Invocations that that mimic key Warlock spells. To keep the Patron spell lists relevant, I think a few Patron-only Invocations would be worth tossing together, too.