Our group's bard plans to take 1 level of wizard at some point (if fits his concept well).
The bard's single level 20 feature (Superior Inspiration) is underwhelming. The only other things they'd get would be the ability to switch a bard spell for another when leveling, and 1 more hp than the wizard.
By giving up that one bard level, he gets:
-Access to 1st level wizard rituals
-A few 1st level prepared wizard spells
-1 1st level spell slot (Arcane Recovery)
-3 cantrips
-Access to magic items available to wizards
Now, the general drawback in taking a wizard dip as a full caster is that you'll gain spell levels more slowly. If there is any single-class full caster in the group, you'll be casting X-1 level spells while they're casting X level spells ever other level (except levels 19-20). This is
huge. A full caster just feels like a chump when he's a spell level behind his peers in the party. However, waiting until level 18-20 for that dip gets rid of that problem (although it also delays the benefits of any dip that isn't designed just to allow high level stuff).
I am a 2nd and soon to be 3rd level hexblade. I can swing the 13 int, but that is not much of a bonus for saves. I would be looking mainly at utility spells and such.
We will see what I choose. From the first, he had wizardry in the background...just not sure if I want to make the jump. If I do, I am only doing one level and all others warlock. Likely to take elven accuracy, great weapon master and charisma bumps...
cannot do everything, so warcaster and the like are probably out...
the game is made well. choices mean a lot and are hard.
As a hexblade, the major downside of taking that wizard level (being half a level behind for purposes of your maximum spell level known) isn't nearly as important for you, because you won't have as big of a dependency on your spells. I'm generally not a fan of level dipping, but this is the sort of situation when it works thematically and mechanically.