Swashbuckler/Hunter w/ Booming Blade, War Caster, and Sentinel Build critique/advice

[Dontmakeit7]

Disclaimer:

From what I have seen, read, and discussed, people tend to agree that War Caster+Sentinel+BB is in fact a possibility when done right. I am not here to debate the semantics on the utilization of such a hella dope combo. I am simply here looking for advice on leveling and features that would be the most applicable for DPR and survivability, based on the presumption that these do in fact work in beautiful harmony. However, I am not against engaging in said topic discussion somewhere else. I would be more than happy to join a thread or PM to continue the topic elsewhere. Thank you.

Intro


So, I've created this dashing and charming Half-High Elf (Using the Half-Elf Variant) Swashbuckler/Hunter with booming blade, and he's going to be a Giant Killer.

With the inclusion of special DM stat bonuses and racial modifiers, my stats are very high:

STR: 12
DEX: 19
CON: 15
INT: 10
WIS: 16
CHA: 20


In addition, we (the party) will be taking Max Hit Die+Con every level.


A quick explanation for the things listed above:


If you're wondering why I'm going with Giant Killer, it's because we're playing Storm King's Thunder (which, from what I have heard, has plenty of giants to kill).
If you're wondering why I was allowed those uber bonuses, it's because we are a party of 3 and the DM is new. He does not want to deal with modifying the book, and seems to think that this in combination with the occasional magic weapon will eventually balance out.


Additional Detail


For this campaign our DM has made available a number of the variant attack actions in the DMG. After I had already created my character, I was especially excited to hear that both the Disarm and Mark attack actions would be allowed but only without consecutive use.

I plan to make our first time DM proud of me by abusing these actions with my character- thus allowing him to lazily effortlessly continue the book as written.

All official content such as XGtE, Volo's, and EE etc. is allowed. UA is excluded, which means no spell-less ranger.

Party Comp includes a human fighter ( has no plans as of right now) and a human warlock (Took MI for the feat and snagged dissonant whispers, what a guy)

The Goal


The goal of this build is to dole out loads of sneak attack damage by utilizing the AoO's made available from sentinel, and boosting effectiveness of OA's with the booming blade cantrip I picked up at 1st level. The playstyle will vary depending on the target. Most humanoids are going to be kited until the fighter requests help, where I will then move in to provide some Sentinel SA reaction damage for the fighter, and War Caster OA's with BB and SA for those who try and run away. Eventually it will amount to the hellasickdope combo of WC+SENT+BB+GK=Big Bad Ded Giant (BBGD).... But I'm just not sure which path to take to get there.

Assuming I take a feat instead of an ASI nearly every time, I plan to have War Caster, Sentinel, Elven Accuracy, and Martial Adept(Riposte and Perry?) by the time I'm level 20.

Elven accuracy is sort of optional, as I have no reliable way of creating adv. I was thinking of taking a +1 to Dex and Con for my 3rd ASI, and then instead taking tough for the extra 40 HP later.

With that in mind, here is the build outline I have going currently.


The Build

Lvls 1-4(5?) / Rogue to Swash (feat: WC/Sent.?)

Lvls 5-7 / Ranger to Hunter (Pick up Giant Killer and shield proficiency)

Lvls 8-20 / Swash (feats in order: WC/Sent ---> ASI/MA, ---> MA/EA ---> ASI/xxx)


Commentary on build

Yes, I realize the fighter can also utilize this build in a similar fashion, but the fighter does not get Giant Killer with SA. IMO when considering the setting, this makes the fighter boring, not as hellasickdope, and the obvious lesser option for flavor.

The Hunter can definitely be taken to 5, and I'm not against having extra attack, but keep in mind that this will prevent me from utilizing BB efficiently. If you feel like this is the better option please feel free to explain why, as I can't seem to think up anything too substantial. (Please convince me so I can take healing spirit!!!)

As far as spells go, I am considering Ensnaring Strike, Hunters Mark, and Zephyr Strike. Let me know if these are wrong or I missed something there.

Conclusion

As of right now, this is where I am. Let me know if I missed anything. If there needs to be more clarification I will do my best to make updates as soon as possible. Please help me and my poor party members survive this book with our new DM.

Thanks in advance.

[Waifu]

The build looks rather solid right now. What I would recommend is trade two levels of rogue for two levels in Hexblade Warlock for at-will mage armor from Armor of Shadows, and repelling blast. Eldritch Blast isn't what you're here for, but what you could do is blast enemies away from you, which forces them to get back into your reach, which helps you get even more mileage out of sentinel. You also get Hexblade's Curse (which does take up a bonus action, but it's an option), and Hex Warrior, which lets you use Charisma to hit and for damage. You will be getting that for -1d6 sneak attack, an ASI, and a 1/rest advantage-to-hit.
Also, on the topic of Swashbuckler, it might be best to dual wield to capitalize on your free disengage from enemies you attack; it might not be optimal at higher levels, though. In fact, I would argue that if you grab multiattack from Ranger, you could forgo dual-wielding altogether in favor for a shield. However, if you go that route with the Hexblade, you will lose another sneak attack die, and proficiency with Wisdom saves. If you don't go the Hexblade route and do grab multiattack from 5th level Ranger, you'll only miss out on one sneak attack die and your 1/rest advantage-to-hit.
The reason why multiattack and dual-wielding would be worth it despite being suboptimal with BB and SA is because of your being a Swashbuckler. It allows you to run into combat, attack as many enemies as you can, and force the enemies to chase you, since you won't be provoking AoO's from them when you retreat, which will definitely help with Sentinel.

[CTurbo]

The Swashbuckler/Booming Blade/Sentinel/WarCaster combo is strong but it takes a long time to come online all the way.

If you take Rogue 4, and then Ranger 3, it would be level 11 before you got your 2nd ASI/feat. That's way too high IMO. So I would either take Rogue 8, then Ranger 3, or take Rogue 4, then Ranger 4 in order to get your combo online asap. I would also take +1 Dex and Con with your 3rd ASI for sure.

If you go Rogue 17/Ranger 3, you'll have 5 ASI/feats, if you go Rogue 16/Ranger 4, you'll have 6.
ASI 1 - Sentinel. I'd take Sentinel first because it's most useful
ASI 2 - Warcaster. Warcaster is nearly useless without Sentinel
ASI 3 - +1 Dex and Con. Getting that 20 Dex is very important.
ASI 4 - ?
ASI 5 - ?
ASI 6 - ?

So other feat ideas. Inspiring Leader would be great on you with 20 Cha. Magic Initiate would also be great for you since you already have Warcaster. Tough is really good since you're expecting to be near melee all the time in order to get max usage from Sentinel. Even Mobile would be good despite part of it overlapping with your Swashbuckler ability, the extra 10ft movement is huge on you. I don't like Martial Adept since it's just one maneuver per short rest and it competes with Sentinel and Giant Killer. I also don't like Elven Accuracy unless you have a very consistent way of constantly having advantage.

About Magic Initiate, you could become a mini Arcane Trickster with Booming Blade, Minor Illusion, Mage Hand, and Find Familiar.
You could become a mini Cleric with Guidance, Spare the Dying or Sacred Flame, and Bless or Shield of Faith. You'll already be really good at concentration saves so either Bless or SoF are really strong.
You could really up your face abilities with Friends, Vicious Mockery, and Disguise Self. Vicious Mockery would be great on you.
You could just choose utility cantrips or Green Flame Blade, and Find Familiar which is extremely useful on a Rogue with scouting and providing reliable advantage. Owl is the obvious familiar choice.

[djreynolds]

The game will go to around 10th or 1th level

Also, when fighting giants, all of you attacks add that extra damage

Grab absorb elements, it is huge

Expertise in acrobatics could be helpful to avoid grapples

Storm King's "Thunder", booming blade may not always be useful

Good luck to you

Uncanny dodge will work nice versus throw rocks

[Diebo]

As djreynolds points out, the game only goes to level 10 or 11. I've been playing for around 50 hours and we are at level 7 (started at level 5 after playing Lost Mines). I recommend you don't build for post-level 11 play (unless you play to continue after this adventure), and don't build for end-game play.

You are proposing a 3-level dip in Ranger primarily for Giant Killer, with the hope that it helps you get your second sneak attack in more reliably.

I think sticking with more levels of rogue will get you to your desired combo of BB and sneak attack 2x/turn faster, and the main damage will come from the sneak attack, not booming blade. For most of the game, you will have a booming blade that adds 1d8 to your damage (4.5 damage), and if they move (which they won't right away, because sentinel drops their movement to zero, a possibility of 2d8 more).

You should be able to get sneak attack twice most turns just through sentinel. With only 3 players and lots of monsters, you can attack, use your free disengage to step back, and be reasonably certain that at least one monster will step up to attack you and trigger your sentinel opportunity attack.

You mention concern with survivability. You are going to be front-lining if your goal is to trigger opportunity attacks from sentinel. That means you need to boost your armor class. 18 DEX means likely 16 AC, 18 AC when you finally get shield. One of the rogues best abilities is uncanny dodge, but that burns your reaction. When a Fire Giant hits you for 28 damage on one of its 2 attacks, you'll want to soften that up/avoid it. Best to avoid that damage if possible.

Can you switch around your stats? If so, for this party (3 people, no healers) I'd recommend a one-level dip into cleric, and theme-specific (and BB-based), Tempest domain. Go rogue first for the skills, then cleric, then stick to rogue for the remainder. One level of tempest gives you:

1. Proficiency with plate and shield. 20 AC.

2. 3 cantrips, 2 spells known, and some cool spell options. Guidance is +1d4 on demand cantrip to most out-of-combat skill checks. Healing Word is a bonus action spell to pick up an unconscious ally. Shield of Faith is a +2 AC (now 22 AC). Bless is a +1d4 to attack (land those sneak attacks/BB more) and saves for all 3 party members. Fog Cloud from Tempest is a giant-blinder (position it in the sky so it blinds anyone taller than six feet or so. Thunderwave is an AOE spell for weak things.

To optimize this, you would need to switch from a dexterity-based rogue to a strength-based rogue, but if you have the availability to switch stats, it won't affect your to hit/damage. Take your 18 from CHA and make it STR, it will be the same +4 you had from 19 Dex. Use a rapier for the same finesse-weapon damage. Drop dex to 13 or higher, keep wisdom at least at 13. With Rogue you don't really need 20 CHA, 18 or 16 would be more than enough (just take expertise in Persuasion and you'll be fine for the social interactions). Even traps will be fine with low dexterity if you have expertise in thieves' tools. With max hit points you could even go 12 CON (15 CON just is 7 more hit points -- 63 versus 70 -- at Level 7, and you will never get your 3rd ASI to get it to 16).

Oh, one final note. I am playing an arcane trickster. My damage is fairly minor compared to the fighter with Great Weapon Master and Great Weapon Fighting. He'll turn on his action surge and blenderize opponents. Giants have a ton of hit points (162 for a Fire Giant). With bless, those blender attacks hit more frequently. A Fire Giant has +11 to hit. Against 16 AC, that is 80% hit rate for about 45 damage/round to you. You can't stand toe-to-toe with a giant for long.

Leveling: At 5th level (level 4 rogue), pick up Sentinel. At 9th level (8th rogue), pick up warcaster.