If you are doing it at the start... why not just have the wizard cast it as an action before they open the door, and do the exact same thing. Or the sorcerer does that without using any metamagic.
You could either be surprised or started at round 2 and not immediately at round 1.
Sure, a brief one, not enough to really make a case for changing anything. And I was refering to my earlier statement. You want to alter how the King is treating you by subtle casting a spell to make him think he is having a divine revelation? You need a charisma check (likely at advantage, but depends on a lot of factors) because you don't get to change someone's actions that dramatically without a check.
I'm sorry, but you can't even force someone to do something with Geas, which is far higher level. I'm not letting Phantasmal force be more powerful than a spell three levels higher than it.
But you can force someone to do something with Suggestion.
Geas' purpose is to force them to do something for an extended period of time, like a long-term curse. Suggestion's purpose is to force the target to complete a task for you out of their will. Phantasmal Force's purpose is to assault their mind with visions in order to change their behavior.
I don't think it requires any sort of check, not at the sorcerer's end. The sorcerer isn't talking or using any sort of their personality. They're using the knowledge on their target against them and hoping they bite. I mean, something so obvious as "I am your god. Uh, give that random guy your kingdom, thanks," isn't going to work on anyone short of idiots. A sorcerer has to be more knowledgeable and cunning, and this amount of work from the player's side should be rewarded.
Maybe the target makes an insight check or a religion check to notice if anything is off or they can make their investigation check, but the sorcerer isn't really using his own personality to convince anyone. He's appealing to the authority of someone else.
So, now your defense is that one of their most iconic tricks was just a ribbon feature and not important. I mean.. they literally are forced to take mage hand, and two of their four features other than spellcasting utilize it. But, most not be important.
Oh, also, they have an ability that specifically only works if they cast a spell while hidden from a creature, meaning that that is something they are expected to do as well.
Its just a parlor trick compared to the ability to have 5 other spells they can cast, 2 of which are at-will and 3 more from a very diverse spell list. I mean, Eldritch Knight gets Weapon Bond but nobody really goes "Wow, Eldritch Knight is so strong. I get to have my weapon on me as a bonus action!" There's creative uses, no doubt, but you won't be breaking any games with it.
Magical Ambush doesn't even relate to Mage Hand Legerdemain since it talks about forcing a save. You can be hidden when you cast a spell, but once you do, you've made a noise and per the rules of hiding, you are no longer hidden.
Its useful for picking locks when traps are possible or doing so behind cover or casting it outside a tavern then walking in. Its not all that useful to cast when engaged in a conversation with.
Sure, but you are basically saying that those slots aren't worth having. You just essentially cast 6 spells (two second, two third and two fourth) and you are treating it like you are being frugal.
I don't get it. I legitimately don't. I have never looked at my 3rd and 4th level spell slots and gone, "Man, these are just cluttering up space on my character sheet"
And, just to point out, if you want to get those spell slots back? You need to spend 28 sorcery points. So, hope you were really confident in needing those points more than those slots, because it is literally impossible to get them back, since it costs ten more points than you gained.
Out of the 22 spell slots you have at level 20, you expect to cast all of them at a distribution equal to the allotted table every adventuring day?
Even if that's possible, spell power goes up by alot the higher your spell slots are (not just damage), so 3 2nd-level spells might not be as combat-ending as a single 5th-levels spell slot. If the sorcerer wants to twin PWK because he's a lunatic, they've essentially turn 3 3rd-level spells into a whole other 9th-level spell slot. This is the most expensive metamagic option. Cheaper metamagics are possible, but you get an idea what you can do.
I've rarely been in a scenario where "I need this spell right now, or we all die" is a thing. And the few times I did (when playing a sorcerer in fact) I had those spells.... because I still had my spell slots. If I've cast two fireballs and we are still in a situation where I need yet another fireball or we are all dead, then I did something horribly wrong with my first two castings, because we shouldn't still be in that dire of straits after I've unleashed my biggest guns at the problem. And if we are? Maybe someone else has a plan will cover it, because obviously Fireball isn't working.
The scenario could happen once every 100 sessions and it would be once too many since that means a 99 session campaign ended because of a TPK. You get closer to these scenarios over the course of a full adventuring day when during the last battle, the cleric is down, the fighter is not within range, the druid is out of wildshapes and the sorcerer has used up all their best spell slots.
Just one extra push could be all you need, so that last fireball may come in clutch. Or maybe its a 3rd counterspell or a 3rd dispel magic.