Regarding multiclassing (ie tri-classing), and more specifically regarding the rogue (assassin) way for a
dex based sorcadin, I suggest the following (not so much theorycraft, rather knowledge gained through
painful playtesting that resulted in numerous rebuilds time and time again).
Some suggestions regarding the pal6/fgt3/rge3/sorc8 build you suggested:
Drop the paladin levels to 2 (or perhaps 3 if oath of conquest is allowed). It is better to exchange extra attack and aura of protection for more sorcerer levels, regarding this build (sorcadin/assassin), since:
1) BB and cunning action disengage. You want to spam that. Granted, it wont always be possible to find an opponent that is not already adjacent to one of your allies, but in many of these cases you will be able to GFB instead (and then move back away via cunning action to safety - this build is squishy, but that's ok since cunning action is here for you).
2) Moreover, with the pressure for dex bumps and for certain feats (detailed later), and due to being MAD (str 13 requirement does not help) and potentially having even less ASI's due to further multiclassing (again, detailed later), you wont have an amazing charisma score. And you want be stiking for long in the front line (since you are squishy, BB and disengage is your bread and butter). So you can drop aura of protection without a lot of remorse.
Drop the fighter levels. It's true, they do wonders for your assassination rounds, but they have a very heavy price on your build's overall efficiency. Your assassination damage is more than solid even without any fighter in the mix. Dont want to get too technical about it, but IME, the real trouble optimizing such multiclass assassin builds, lies in making them overall useful and dragging them away from the trap of being a one-trick pony. There is also a certain point at which assassination damage stops being friendly to playing a group game. Bottom line, after you make sure that your assassination damage is at good levels (guaranteed with divine smite and quickened spell in place -twinned spell can help here too, if the enemy positioning allows for it), you are better off starting
optimizing other aspects of your build, such as how to trigger assassinations more reliably (particulary through the aid of magic), or how to be more efficient during encounters when the surprise round passed/ didnt apply (ie develop strategies and tricks to help yourself and/or your allies become better at stuff).
To accomplish both of these (ie the underlying part right above), the best way to do it IMO is by
investing heavily in the sorcerer class. Spellcasting and having more sorcery points is all you really need. So a
paladin2/rogue3/sorcerer15 is almost as good as it can ever get. Personally, I find that
a 1-level dip in warlock mainly for AoA is just too good to refuse, since the resulting character will be rather squishy (though nabbing hex is useful too as it can potentially lower an enemy's initiative, and a couple more cantrips and one 1st lvl short rest rechargable spell slot aint nothing to frown upon either). So for me, the ideal build would be
pal2/rogue3/warlock1/sorcerer14, with the warlock level being picked no earlier than the 14th character level (dont want to get too technical about it at this point, but you are better off dipping in warlock once you have high enough spell slots with which you will upcast AoA). Perhaps, now with the oath of conquest that gives us AoA at level 3, I might consider a
pal(conquest)3/rogue3/sorcerer14 too; oath of conquest might not give you hex, cantrips and a spell slot that recharges on short rests, but the channel divinity (the once granting +10 to an attack at no action cost) has wonderful synergy with assassination, so there is a real dilemma wether to go with a 3rd paladin level for conquest oath, or with 1 warlock level, as both have its pro's and con's. Either way, that level (paladin 3 or warlock 1, should be gotten preferably
after you hit pal2/rogue3/sorc8 - ie after you have high enough level slots to use AoA with, and without delaying getting access to the all powerful gr invisibility and to one more ASI which are rare and precious for this build - at sorcerer 7 and 8 respectively).
As far as
feats/ASI's go, I think it is almost self explanatory that
dex should take priority over charisma, and since there are a couple of feats that assassins can really profit from (and adding that you are as MAD as a character can get and that your multiclassing doesn't help with getting lots of ASI's), I dont think charisma bumps are good enough to be on the menu. But this is not a really devastating thing, as
you can focus your sorcerer magic on utility and buffing (with a bit of debuffing as back-pocket tricks). So depending on choice of race,
expect your charisma to start at stay put at a 14-16 score.
Even dex might not get up to 20, since
alert and
lucky are too good to not include on your final build. Alert for obvious reasons, and lucky..... well, lucky is perhaps the feat that is being utilized best by assassins than by anyone else. Rolled badly on a stealth check that is important for surprising an enemy? Reroll. Rolled horribly on initiative? Why risk it (assuming a very good initiative bonus)? Reroll. Rolled appaulingly on a surprise round attack? Reroll. Plus all the normal rerolls regarding attacks, saves and checks that apply for any other character having this feat. So
alert, lucky, and one dex bump probably is the best you can hope for (assuming NOT vhuman).
Regarding
race and sorcerous origin (yeah, these two go hand in hand), if allowed
shadow sorcerer (which is the best one imo), you can go
vhuman for one more ASI/feat (possibly another dex bump to raise DEX to 20, though personally I also quite like resilient con to round out my stats and to boost my concentration that is crucial for keeping my concentration spells working - yes, expect to make regular and good use of concentration options, you can dubble at buffing, remember?). Shadow also allows you to duplicate the darkness&devil's sight trick, and this is especially good on someone with access to cunning action (hide), such as this buid. Though in the case of a vhuman you will go with a charisma score of 14.
If shadow is not allowed or you dont want it for whatever reason, then going with a
race that grants darkvision is pretty much mandatory, so you dont get that extra ASI. On the plus side, your charisma will most likely be at 16 (possible candidates are the halfelf, drow, feral tiefling, etc -anything with darkvision really, as much relevant stat bumps as possible, and useful/flavourfull racial features). Also, if not shadow sorcerer, you might want to look at
favored soul origin. Strictly inferior to shadow (as every other origin regarding such assassin builds) imo, but it's the only way to nab
scrying as a spell through either knowledge or light domain (I simply love scrying on assassins!!! Also, knowledge domain is better, as besides scrying it gives you access to non detection and arcane eye, both very powerful on assassins).
ps:
No warcaster means going with a
rapier/scimitar/shortsword
and a free hand (You can grab a shield if you include sublte as your 3rd metamagic at sorcerer 10, but there is something about assassins carrying shields that doesnt quite hit the right flavour for me).
Regarding
metamagic,
quickened and
twinned are the best two starting options. Both can hep with assassination rounds, or rather you can say that quickened always helps and is crucial for assassinations, while twinned has the potential to help with assassinations. But twinned can be incredibly useful, if you only start considering your choices of spells and your combat tactics. To jump a bit ahead here, given how you can BB and disengage via cunning action every round (yeah, this build results in a very mobile playstyle), twinned spell for twinned BB immediately becomes one of the most efficient use of sorcery points. Moreover, you will be relying on buffing spell for your concentration (like greater invisibility and perhaps one more chosen between haste and polymorph, for when greater invisibility would not work against an enemy), so twinning any of these is again, awesome! You have the sorcerer levels/points (at least in the mid to long run) to back such tactics up. Will expannd more on this when talking about combat tactics.
For the third metamagic, I am quite fond of
subtle. Careful and heighten both have their merits (perhaps heightened less so if you went with shadow sorc due to that wretched hound), but there is something about subtle that I simply like too much, and imo it fits the theme of a ''magic'' assassin a lot (regardless if your DM is strict or not concerning
if casting hex breaks stealth). Using subtle to bypass the somatic components so that you can equip a shield is not worth it generally imo, regarding this hit-and-run build, though it must have some situational value in it (I guess...).
Anyway, subtle spell allows for a lot of creative uses, and for those there are really not guidelines other than your own imagination. Nevertheless,
here's a story that presents a very good application, which I admit was of extremelly situational value.
Spoiler: A very situational use of subtle&creation
Show
Being extremelly jealous of how bladelocks can summon a blade (ie their pact weapon) out of thin air, I decided to include creation on the (sorcerer) known spells of my assassin. And I did that just when I hit sorcerer 10, at which point I also picked the subtle metamagic. Long story short, my character was caught spying Mr Bad Guy in his own castle. After several in-game days of my poor character being tortured and mutilated (losing one hand while at it), Mr Bad Guy decides to play the good cop card and gain the information he wanted out of my character by being all polite and civil. So there we are, me and Mr Bad Guy, and about a douzen of his guards, trying to enjoy tea and making small talk in one of his castle's living rooms. Naturally my character (who was low on hp, resources and was suffering a few exhaustion levels) was cuffed (no favours for cripples I suppose...), but other than that no extra precautions were talken since it was not assumed that my character was a high level spellcaster (yeah, DM was generous at that, though to be fair, my spell list consisted mainly out of utility options and was entirely lacking damaging spells and some excellent pickups like animate objects). Small talk starts turning into negotiations, roleplaying is being done and rolls are made (persuasion and deception), when at some point Mr Bad Guy makes a pause and asks:
Mr Bad Guy: ''So, how is the tea?''
Cyria (my char): ''To be honest, a bit bitter for my liking.''
MBG: ''Well, that's what sugar is for.'' (and instructs his butler -who turned out later on that he was the real bad guy.... yeah, it's always the butler!!!- to bring me some sugar for my tea.)
Me to DM (OoG): ''Wait... they gave me a spoon along with the sugar???''
DM:'' Yeah, sure. But it is a very small and very cute teaspoon. I know what you are thinking, and it's not going to work. If it had any chance of working the guards would be more alert, and you probably wouldnt have it, especially while being uncaffed. You cannot use the teaspoon to assassinate this guy, no more than you cannot use your bare hands to the same effect.''
Me to DM (after taking a brief moment and a quick look to the PHB to see if what I actually have in mind can actually work): ''Ok, fair enough. I start casting with the subtle metamagic a spell that will take a full minute to complete casting. All the while, my character pretends to listen to Mr Bad Guy's rambling'', that was just about to intensify into a megalomaniac self-promoting speech.
The DM seems intrigued by what I have in mind, and decides to play along, waiting to potentialy be surprised along with Mr Bad Guy from what I had in the works. I am required to roll a deception and a concentration check, in both of which I suceed (at that point we had both forgotten about exhaustion, but probably that was for the best, as the whole thing succeeding made for a very entertaining story). The full minute passes, and Mr Bad Guy's speech finishes just I have finished subtly casting creation to transform the round edge of the teaspoon into a sharpened one (RAW it works, as long as the very small and very cute teaspoon that I was not able to use my assassination with, passes off as a tiny piece of matter for the purpose of being the material component for casting creation). At which point, Mr Bad Guy asks emphatically:'' WHAT DO YOU SAY TO THAT?!!!''.
Granted, my character had no idea what he was talking about, as she was only pretending to pay attention while focusing all her effort at casting this spell. Out of game, I had no idea either, as the DM would only perform a few random isolated phrases and words that my character was able to catch while casting her spell.
My character's response was to pull out the sharpened teaspoon, and gathering all her remaining strength make a sprint towards Mr Bad Guy, proceeding into two quick stabs (making use of quickened metamagic), finding his heart with the second one and dropping him dead on the spot (Mr Bad Guy had just a little more than 100 hp, though he was strong in other ways, such as being very rich, politically connected, have a small army, and so forth).
The butler immediately ran, and the guards lost the earth under their feet for a brief moment, before one of them finally shouted to the others: ''KILL HER!!!!!!!!''. Now, my character was very low on hp and slots (I remember I had no sp left and I only had a couple of 1st lvl slots at that point, after having to blow a 6th level slot on creation cause I had no other high level ones, and a 3rd and 4th on smiting, if memory serves right), and there was no way she could make it out of there alive, since the guards were not looking very talkative. That mini-session between me and the DM, ended about half an hour prior to the normal session (where all the group would play) that was programmed for later during the same day. I was already playing a substitute character from the point that my main character was taken prisoner, and was helping the group with their plan of finding a way to rescue my main character (which was not a very easy task). No need to say, that when the group gathered, I informed of what had happened and that we were working on a time limit (I know, I know, very metagaming, but I loved my character and I wanted her saved). Thankfully, the normal session went well, as did the efforts of the group trying to rescue my Cyria, and the group finally managed to burst open the doors of that living room at the exact same moment when the guards were ready to jump at me (I know, what a coincidence!:smallsmile:), making for a very last minute rescue and a happy ending for everyone, apart from Mr Bad Guy, several of his guards, and my substitute character who after that session had urgent bussiness of his own to take care of and stepped away from the spotlight (until he made his return as an NPC, and an important one at that, later on in the campaign).
Things I've learnt from that experience:
1) I will always aim for both subtle and creation if I ever again make a sorcerer (particularly one that dabbles at assassinating), no matter how situational both of these may be (I simply got to love them and pay tribute to them for what they did for me).
2) Never, ever, ever, split the party. Even if the party agrees it's a good idea and the DM says it wont be a problem playing the occasional mini session on the side. Always stick with your group! Always! (Unless perhaps they are dying one by one and you have a reliable escape option, then feel free to ditch them and save your own skin -lawful good need not apply).
Regarding
spell selection (copy-pasting from an old post and adding a few bits here and there):
(
These are definitely not the most optimal choices, I purposely omitted a lot of good spell -animate objects is the first to come to mind-, just to include spells that I liked more when playing this character. And
I only played this char up to 15 level, ie pal2/rogue3/sorc10. I do support some of these choices as optimal though, such as
greater invisibility,
invisibility and
etherealness, but this section is meant to just give a very rough guideline, in that
the mediocre charisma shouldnt scare an sorcadin/assassin from investing a lot in sorcerer, as the sorcerer's spell list provides the assassin with tons of useful tools for making him better at both assassinating and at anything else from combat to social interactions, etc)
Spoiler: Some useful spells
Show
(The order is mostly random)
1) Invisibility. Definite pick for assassins! It is so good, that makes me thing that it is a real shame that singleclass assassins dont get it via class, and cannot even get it by a feat, and thus need to dip 3 levels. Lasts for one hour. Dont be afraid to use it (even if you have to upcast it to bring friends with you). Easy surprise rounds!!! Oh, and happy scouting...! ps: expertise in stealth.
2) Greater invisibility + cunning action hide + BB + move freely without provoking AoO because you are unseen will be your best use for concentration and your best combat strategy, unless your enemies have any special senses (typically some strong enemies have such powers). Misty step (for anti-grappling) and counterspell will be your best defenses, while you attack everything with advantage and are practically untargetable. Which reminds me. Definitely expertise in stealth.
ps: Definitely twin it if you have another rogue in the party. Or twin it to include a GWM or a SS (burns 4 sp so be careful though, reserve twinning it for when it matters).
3) Quicken hold person as bonus action (cast at a higher slot to target more enemies - especially if some of them are close to one another so you can autocrit with twinned cantrip and double smite) and autocrit madness means bringing your assassination online when you wish for. Plus your martial buddies will thank you, and it is also good CC. You dont have extra attack, but it is still a good alternative use of your concentration, if only a bit situational. Best used when you need to bring a/some humanoid(s) down fast (eg, kill the guard that survived your assassination round before he rings the alarm). Upcasting at least by one level is crucial to make it landing at least at someone more reliable, since you dont want to risk spending 2 sp and a spell slot for nothing. Extra points if two enemies affected are at least 10 feet from each other, as then you can twinn BB with your main action (assuming you quickened hold) and stack smites against both of these enemies. So make sure to include enemies whose positioning allows for twinning BB, when upcasting hold person.
4) Shield is one of the best reactions. You get it from sorcerer level 1 (sooner than uncanny), and makes up for missing on uncanny dodge by staying put at rogue 3. Furthermore, if you employ a lot greater invisibility (and darkness if shadow), and you should as it is the best combat tactics around for mobile( ie cunning action disengage) and sneaky (ie cunning action hide) builds as this assassin, being attacked with disadvantage raises your effective AC, and that makes shield work better that first assumed, when looking at a base AC of around 17.
5) Dimension door for easy way in, easy way out. (makes the job of an assassin a lot easier)
6) Misty step for ensuring mobility when terain is tricky, or when someone is grappling you. Which reminds me. Get athletics or acrobatics training, you must have at least one of those skills (if not expertise as well). Also, your squishy build relies on mobility, being gappled can hurt you a lot. Having a way to escape grapples without wasting an action is awesome! Plus, I could not even begin describing how this spell has helped my assassin when being chased in urban terrain.
7) Counterspell, because in all honesty it is an amazing spell.
8) And mirror image for some extra survivability when you need it. Remember, you are not a tank, you actively try to avoid being targeted (BB + cunning action disengage + move away), so mirror image wont burn out too quickly. Blur is better for tanks who lack better concentration options. You are no tank, and you have better concentration options (hold person, greater invisibility). If you wanted a tank, you shouldn't play this build. Self buffs like mirror image and armor of agathys, work well with quickened spell metamagic option.
ps: I think mirror image is a panick button, as Gastronomie describes it somewhere in his guide. Granted, I dont value it as much for tanky sorcadins as Gastronomie, but for builds such as this assassin, that actively tries to avoid being attack by moving around in the battlefield, it is a fantastic spell to have, and strictly better than blur. Blink is also a good substitute for mirror image, but its randomness makes me prefer mirror image. Either way, you might prefer blink, but dont take both, one or the other will suffice.
9) Alter self takes care of a lot of your social stealth (just make sure to expertise deception). This and invisibility are like bread and butter for assassins. Disguise self has some pro's over alter self, but the fact that alter self does not require of you to take the actor feat to change your voice makes me prefer alter self over disuise self.
10) When gr invisibility (and darkness) is not working against a creature, you better have another good of concentration at the ready. Since you have twinned, and since you will have a lot of sorcerer levels, it makes sense to take a buffing spell with which to buff your allies. Haste and polymorph are the two best options, pick the one that suits the builds of your partymates better. For example, if you have two allies with GWM/SS, it makes a lot of sense to pick haste, while if you have a lot of squishies it makes a lot of sense to pick up polymorph. Just make sure (especially in the case of haste), that you dont lose concentration of what you paid with sp to do. Casting mirror image on the following round and trying to always stay at a distance from powerful enemies via cunning action disengage should be your plan, especially when you twin-buff allies.
11) Creation, just because of the story I described. Got to pay tribute...
12) Disintegrate, for situational use and for style points (plus, disintegrating a dead body = no evidence, so that might be ocassionaly useful in your line of profession. Use it with the hound of shadow sorc, or with heightened, or quicken it after you succeed netting a target (attacking from darkness or when invisible helps land the net attack, as it cancels out the disadvantage). This will hopefully make up for you mediocre charisma (14-16). And make sure to use it situationaly, meaning that you should only use it against enemies that seem slow (ie low dex save).
13) Etherealness: The sooner you will get this is at 18th level. Seriously though, this is like the dream capstone of any assassin. I cannot imagine making an assassin with spell support and not plan for this spell at the high levels. Granted, I have not tested this in actual play, but I'd be surprised if it didnt turn out as a major boost. The fact that from the moment you get it you can already upcast it (cause of the 2 paladin levels in the build), makes it even more awesome. This is another reason (although not the main one, the main reason is more spells and more sp to use with tactics such as twinned greater invisibility, twinned haste/polymorph, twinned BB and disengage, quickened hold and smite, or with my assassination by quickening a scag cantrip, moreover, quickening mirror image as a panick button, etc etc etc) as to why I wouldn't drop my sorcerer levels lower than 13.
There are many other useful spells, and I suspect it wouldnt be that difficult to create a more optimized spell selection than the one I presented above (which includes many of my favourite spells). For example, it is evident that the spell selection is missing an AoE, which can be situationaly very useful even if we dont have a superb charisma. I took measures and put a lot of effort to ensure that the spells taken are such that they make good use of my spell slots (regardless on if I can turn spell slots on sp), and that I dont end up with more concentration options than trully needed.
But, as I said, there can be made a lot of improvements in this spell selection, wether it is to hit a better optimization point, or to suit personal preferences. For example, if someone goes with FS origin (light or knowledge), nabbing scrying and later on teleport can be quite fun and effective too, for some scry and die tactics.
As far as
progression I would probably start as a paladin for wis save prof and for the few ore hp (though I can see an argument made for starting as sorcerer for con save rof, even perhaps with rogue for the extra skill). Anyway, no matter with which class you start, I think you should be a pal2/rogue3/sorc3 at character level 8 (to have all of assassinating, divine smite and metamagic in stock), and then proceed all the way with sorcerer (possibly adding 1 warlock level
OR a 3rd paladin level for oath of conquest, at some point after you hit sorcerer 8, ie character level 13, for not delaying at all greater invisibility and the ASI; You do that in order to get AoA which will help A LOT with the survivability of this squishy character, but eactly when you do that, and if you do that, will depend a lot on your patience of postponing the higher level sorcerer spells and delaying getting more sorcerer points. Theoritically, I think the best time to do that is at 14th character level, though this will depend a lot on your campaign and how difficult it is for your character to survive encounters).
If going with shadow sorc (and started as a paladin), plan for pal1/rog2/sorc2 @ char lvl 5, for both darkness and cunning action (this will carry you through many battles till you get access to gr invisibility; if your group is hurt by this, drop it and start using bless more, till at least you get acess to other concentration spells, though do try to make darkness work, it is good along with cunning action and BB). If not going shadow sorc, then try to include at least 1 sorc level and 2 rogue levels by character lvl 5, do that for the BB + disengage tactics. Preferably delay that 1st sorcerer level up to level 5, and till then (ie till level 4), use a shield.
While the
final build, should be something like
paladin2/rogue3/sorcerer15, or
paladin2/rogue3/warlock1/sorcerer14, or
paladin3(conquest)/rogue3/sorcerer14, I would say that it wouldnt be exactly wrong to go with
paladin2/rogue3/sorcerer13 and spend the remaining 2 levels however else you want. Sure, fewer sorcery points are not doing you any favours, but you could use these two extra levels to nab an extra feat, or for something you have in mind and that you really like. Just make sure to keep those levels to a maximum of 2, reducing further the sorcerer levels will be bad, as you will be losing more sp, spells -like etherealness-, and spell slots (for example, a build like paladin2/rogue4/warlock1/sorc13, loses the 8th level spell slot that the build paladin2/rogue3/warlock1/sorcerer14 has for example.
Track down your spell slots, upcasting can go a long way).
Hope any of that is of any help regarding fleshing out a bit more the multiclass section.