I don't care. Eldritch Repo folks are being sent

When clerics betray their gods they lose their powers

When warlocks betray their gods they gain a target on their back

Yeah. It's way more fun to leave their powers intact and send wave sheet wave of eldritch horrors bent on revenge after them.
- My autocorrect also frequently turns "after" into "sheet" and it's funny to see it happen to someone else.

Eldritch pacts are meant to be agreements between a master and an apprentice, kind of like the Sith, or tradesmen in real life. The Warlock receives knowledge and resources from the Patron, and the Patron gets the Warlock's service in return. If the pact is broken, the Warlock loses the ability to continue to learn from the Patron, leverage their resources and influence, etc., but they do not lose the knowledge they've already learned (unless that was a specific stipulation in the pact).

This makes sense. It also makes Warlocks different from evil clerics.
I could definitely see it going either way. That being either the patron bestows knowledge, or the patron actually provides the power in real time.
But it should be something that is agreed to between the player and DM as soon as the class is chosen.
- Oftentimes warlock levels don’t make sense given what happens in-game. I’ve rarely seen anyone talk to their patron for any length of time to get the tips n’ tricks necessary to increase their level through “apprenticeship.” Even coyly saying “I seclude myself for a few hours“ seems to be too much for most players. You have a mechanically built in RP opportunity, folks, use it!
- In the playtests of old Warlocks were intelligence casters and some of the flavor stayed. Made more sense to be a researcher that strikes a deal for knowledge while a charisma one would be more inclined to bargain for straight up power.

Clerics have a pray each morning and their deity grants them some spells for the day, meaning if the deity is unhappy it can deny them today's spells. Warlocks have been given the knowledge of how to cast some forbidden magicks, they don't need their patron to give them permission to cast what they already know. If a warlock pisses off their patron then they'll have to come down and rip that knowledge out of their head with their slimy tentacles, which sounds like a great plot, I've got some writing to do...

Warlock is given the power too. You wouldn't be able to bargain your spellslots back of it didn't come from your patron.
Also, if it was knowledge based, you'd use your intelligence, not your charisma.
- Warlock was apparently meant to be an INT-based caster in 5e, apparently the grognards didn't like change so they reverted it after the dndnext playtest (but forgot to change all the starting proficiencies!) It makes more sense for the "mad mage who studied the forbidden magicks" archetype though.
That's a great way of describing it.

I don't think it's great for any class to take back powers that the character has earned. Not even clerics. For as long as there have been religions, there have been schisms and power plays. It even ruins possible intrigue involving religions if you can tell what follower of a good god has gone astray by asking them to cast a spell.

There are more interesting ways to do consequences for defiance of higher powers than to hold their abilities hostage. That feels less like the consequences of a living world, and more like the DM yanking the player's leash.

But I can accept that this is an established system/setting thing for clerics and paladins. For warlocks, it is not.

I like the idea of the cleric being required to do some kind of penance, on the threat of losing their powers.
- Pretty sure they have rules for this in 3.5. I know they do for Paladins that get off alignment (it's also how you make some prestige classes to create an "evil" paladin or death knight or whatever it was called).
  With Warlocks, I feel like the punishment could be anything, as the devil's contract would likely stipulate exactly what happens if you fail to obey the patron. Maybe you lose your powers. Maybe they draft you into the Blood War. Maybe they just take your ass to the Hells.
- In general, you don't want a player to loser their powers. But if you can turn the threat of losing their powers into a plotline, then that's awesome. Warlocks losing powers for breaking contracts is bad. Warlocks having to fend off eldritch repo folks for breaking contracts is good.
I did have a game where the warlock lost all their powers and went down to a level 0 commoner, but that lasted for something like 2 days irl and it was because my fighter killed his patron. He's a cleric now

I really feel like it's dishonest for players to argue about this. The one to decide is the dm. Trying to bully the dm into a position where the player is guaranteed anything when the class purposefully places you in the hands of the dm is not cool imo.

Like, ok guys, you want to play a tactical wargame and you don't care about any lore or world building and the dm is your opponent. But why do you play a warlock, a paladin or a cleric if you want to be an ass about it?

This along with Clerics and Paladins also potentially losing their powers are better left up to individual tables to decide if and how they want to implement

Ultimately D&D is about telling stories. Does the player want to tell a story about having his character lose those powers temporarily? If not, you can just say that the contract is to sow chaos or something else vague and almost impossible for an adventurer to fail at.

(Or maybe have a supernaturally evil entity simply grant the magic for free, no strings attached. Having Satan give you great power with no explanation might seem even more menacing than a conventional agreement to do evil.)

Beyond that, game rules can't fix bad roleplaying. The right answer to immersion-ruining, unfun in-game behavior is an out-of-game conversation with the player, which might need to end with "...and stay out!"

Plus I think its unfair that some classes are bounded to strict conditions and some not. Why doesnt the artificer or wizard able to lose their powers then if the cleric or paladin does ?
I agree with you. If the player agrees to it, sure go ahead. As a bad surprise or a bad consequence of something else ? Find something that would affect anyone the same. Like jail.
- Well the wizard loses his spells of he loses his spellbook or spell components, or at least that's how it used to be.
  Got nothing for the Artificer. It would be cool if they had tools or something like that they used. But I don't think it's about fairness as it is about immersion. Depending on the patron, especially the ones all about planning or intelligence, it breaks some people's suspension of disbelief that they would make such dumb contracts that allowed the person to keep powers or gain new ones after betraying them.

The term "warlock" comes from a root (Old English, wærloga) that literally means "pact-breaker".

So I'd say it's very much in the spirit of the class to eventually betray one's patron.

Right, but they're specifically talking about breaking your pact with (the Christian) god. Like, y'know, the devil did. Warlocks were devils, not protégés of devils.
And get punished for it
- Oh mister patron I have been soooooooooooo bad.
- Sure, within reason for the setting. There is a reason that their patron has them in the first place, and I'm betting until the warlock did the betrayal, the reason was something along the lines of "can't act directly in the mortal realm" or somesuch. As long as this isn't a 'god's wrath falls, warlock dies' moment, there is a lot of room for fun in how a warlock might have to start dodging other warlocks or mystical beings the patron can act through.
- I mean, part the deal is likely that whatever you cut a deal with gets a new chew toy for eternity upon your death
  So you know, benefits now punishment later

Wait. Hol'up. Just. I'm gonna stop y'all right there.

What. The actual. Fuck?

If you can somehow betray your patron (eldrich gods may not give a singular fuck about what you do), I'd rule that your spell slots become same as sorc spell slots, no short rest recharge, no "only max level". And if you die, your soul is immediately claimed by your former patron.

But frankly, people don't seem to interact with the whole mechanic much.