I wouldn't call it broken...
...but I would say it is not very fun as written.
The class is the most front loaded class in the game. It is really good if you are going to be doing a low level campaign and never go past level 3. After that it just gets boring.
I feel like the core of the class is being a slave to a eldritch creature in a quest for power. There needs to be a greater sense of a Faustian pact. The flavor text says this explicitly but it doesn't come through in the mechanics. The player needs to pay for that power in a thematic way. Possible ways to implement (this is just spit ball ideas):
Patron requires that you cast a spell from a certain school in each combat. (it would never be Eldritch blast)
Patron requires that you burn every location where you have a combat or sleep so there is no evidence of your passing.
Patron requires that you ...
Basically, you need a way to keep being a Warlock from just being easy mode. Paladin is restricted by his alignment. (at least he used to be), and the fact that he is kind of a jack of all trades master of none. When I DM, I always make the Paladin earn his alignment by presenting him with moral quandaries frequently. If he fails he loses his power until he re-earns the favor of his diety. (Yes, I'm like that)
I suppose you could do something similar with Warlock but if you are using a pre-made module that is kind of tough. But in a similar way, there needs to be a sense that the Warlock is in a Faustian pact or it is just "mage in easy mode". This would be different than a Paladin, if a Paladin abandons his path he is just a bad Fighter. If a Warlock abandons their path they are now going to be taught a lesson from an eldritch titan.
...but I would say it is not very fun as written.
The class is the most front loaded class in the game. It is really good if you are going to be doing a low level campaign and never go past level 3. After that it just gets boring.
I feel like the core of the class is being a slave to a eldritch creature in a quest for power. There needs to be a greater sense of a Faustian pact. The flavor text says this explicitly but it doesn't come through in the mechanics. The player needs to pay for that power in a thematic way. Possible ways to implement (this is just spit ball ideas):
Patron requires that you cast a spell from a certain school in each combat. (it would never be Eldritch blast)
Patron requires that you burn every location where you have a combat or sleep so there is no evidence of your passing.
Patron requires that you ...
Basically, you need a way to keep being a Warlock from just being easy mode. Paladin is restricted by his alignment. (at least he used to be), and the fact that he is kind of a jack of all trades master of none. When I DM, I always make the Paladin earn his alignment by presenting him with moral quandaries frequently. If he fails he loses his power until he re-earns the favor of his diety. (Yes, I'm like that)
I suppose you could do something similar with Warlock but if you are using a pre-made module that is kind of tough. But in a similar way, there needs to be a sense that the Warlock is in a Faustian pact or it is just "mage in easy mode". This would be different than a Paladin, if a Paladin abandons his path he is just a bad Fighter. If a Warlock abandons their path they are now going to be taught a lesson from an eldritch titan.
