So, I've wanted to do this for a while ever since Swashbuckler came out, but I never got the chance until now. Unfortunately, I always get stuck on how many levels I want to put into what, and since these forums have helped me in the past with this sort of thing, I might as well ask again!
The character concept is Lokhir Felheart inspired; a dual-wielding pirate lord with skills as a duelist whose prowess is further enhanced by magic.
I plan to pop him in at Level 5 at Rogue 3 / Warlock 2 as a prepared replacement for another character who I have.
So, does anyone have any thoughts or ideas? How should I spec him for future levels?
I am no expert of this Lokhir guy, but from an optimization point of view assuming you want your physical weapons to be your main attacks, you want at least 5 levels of warlock for an extra attack. Since rogue gets their most powerful feature at level 11 I would say Swashbuckler 11/Hexblade 5 is a good foundation. What you do with the last 4 levels is a lot less obvious. One synergistic version would be Swashbuckler 12/Hexblade5/Battlemaster 4.
If you take the see-through-darkness Invocation make sure to have darkness as one of your spells, and a melee char with counterspell is never a bad thing.
I’ve been theory crafting a rogue/lock myself, though what I have a little different but with what you have in mind I might suggest going pact of the blade and taking the thirsting blade and Eldritch smite invocations when you reach level 5 warlock that way with duel wielding you’d have a total of 3 attacks per round and throw the hex spell into the mix you’ll be adding an additional 1d6 per hit with the option to add more damage if you so choose. Now if you also want look at the shadow blade spell as it might also be something you’d be interested in. Since you are going to be melee if might be a good idea to max out con and take the tough feat so your character doesn’t have a glass jaw and can take some damage with our worrying about going down.(I’m building a 4fiend lock/3 trickster with a 16 con with tough average hit points would be 75 at 7th)
edit: I forgot to also mention with hex blade you can have both your hex blade and pact weapon at the same time, and your pact weapon also receive the same benefits with char to hit and damage
Not aware of thr character your mentioned, but i have some suggestions for hex/swash and pirate themes
1. You dont get two weapon fighting style, so if its not a core character concept i would personally shift to using booming blade with either a scimitar or rapier. Dual wielding does give you a second chance to hit, but later on swashbuckler gets that anyway. Booming blade is very powerful on a swashbuckler because you get the free disengage, meaning you can still dash away or do other things with your cunning action.
2. Dual wielding doesnt work with hex warrior. Of you use a single handed weapon you can go all in on your charisma to be the most suave pirate you can be, and rely on medium armor with 14 dex for protection.
3. If you do go further in warlock, you can see if your dm will allow the imp familiar to turn into a parrot instead of a raven.
4. Mask of many faces + expertise + friends cantrip is a very powerful combination. If you play it right you get the target mad at either a random person or at your enemy while still getting information or favors. Your other invocation could be misty visons for easy concealment, or maybe devil sight or whatever else you fancy.
I've been playing a swashbuckler through a long campaign up through level 12. Thirteen, I wanted something different. Talked my DM into my character making a dark pact for hexblade multiclass. Through my adventures, I've got 20 Dex, 18 Cha, a+2 Cutlass (rapier reskin), magic initiate for find familiar and booming blade. I dip into hexblade and get a shield and mage armor cause I'm a bit squishy. Devil sight and darkness spell. I'm attacking with +12 to hit. Doing 3d8+6d6+7 damage on one hit. With advantage in the darkness. Free to move away, and 3d8 if they move. She hits like a truck. Not many HP, but a cloak of protection helps make me hard to hit. I love it.
I’ve been theory crafting a 15 swashbuckler/ 5 hex blade scourge aasimar. I chose that mix because I wanted the 8d6 sneak attacks, access to 3rd lvl spells, second stage cantrips, being able to focus cha and con with only 14 dex, and 3 invocations specifically. Booming blade and eldritch blast are core, with a third cantrip of choice. For invocations I decided on grasp of hadar, agonizing blast, and lance of lethargy. You could take the added attack but it adds pretty little damage when not using shadow blade. The last option I would consider is eldritch smite to get even more 1 shot potential, but I wanted my character to be better at chasing people down so I went with the additional cc. Booming blade lets you move for free or damage them after you pull and slow them with no save. Hardcore duel potential with scourge for added damage and aoe.
Currently playing a Halfling Swashbuckler / HexChain and it is darn effective. I am the front-line fighter and chose to use a shield as well. I have a lot of in game versatility and can hold the line. I picked up booming blade, shield, and absorb elements for a well rounded defensive strategy. Eldritch Blast enables me to have a reliable ranged option if needed, but I usually can get within range and rapier the heck out of any enemy in high flying fashion.
I find the Chain option adds a silly amount of character versatility and keeps me from being a one trick pony. Keeping an invisible ally that can provide you with the help action every round is also a massive boon to your one attack. My familiar is usually invisible and flying directly above my position ready to cause annoying distractions to my opponent like positioning rocks under their footing, bumping into their backs when they are maneuvering, or wafting a foul breeze into their faces to help. The scouting and general helping hand an advanced familiar can offer in and out of combat is only limited by the imagination of the player and allowances granted by the GM. It is a class feature after all, and should be treated like one instead of just a spell.
Rollback Post to RevisionRollBack
IMHO, Earthdawn is still the best fantasy realm, Shadowrun is the best Sci-Fi realm, and Dark Sun is the best D&D realm.
Thirsting Blade, which is the Warlock equivalent of Extra Attack, only works with Pact Weapons (and requires five levels in Warlock).
If you do have five levels in Warlock you can take Pact of the Blade, summon one scimitar as your main hand weapon and keep the regular scimitar as your off-hand weapon, however that's really going all in on Warlock. It's why I've come to regard multi-classing as a bit of a trap (unless it's something like a single level in Hexblade for a College of Swords Bard).
1. You dont get two weapon fighting style, so if its not a core character concept i would personally shift to using booming blade with either a scimitar or rapier. Dual wielding does give you a second chance to hit, but later on swashbuckler gets that anyway. Booming blade is very powerful on a swashbuckler because you get the free disengage, meaning you can still dash away or do other things with your cunning action.
Just fyi if you didn't know, booming blade doesn't activate unless they willingly leave your melee range. You'll still get your on hit bonus though, of course.
Unfortunately hexblades don't lend themselves well to dual wielding because the cha bonus can only be applied to one weapon. However, if you want to dish out lots of attacks you could go for a double-bladed scimitar through the pact of the blade boon. With the corresponding feat this counts as a finesse weapon, letting you deal sneak attacks and functionally be dual wielding.
just so you know the cantrip scaling works with your total level, not your level in the specific class. So you'd actually have fifth stage cantrips with that build, cantrips are one of the few things to scale with total level.
For those coming across this now, here is my experience playing Swashbuckler/Hexblade. For my concept, the character is more Swashbuckler focused than Warlock focused, so I at lvl 8 I am Swashbuckler 5/Hexblade 3. I went with a variant Tiefling, Devil's Tongue, for flavorful spells: Vicious Mockery, Charm Person, Enthrall are all great on a dashing Swashbuckler type. Stats for this character I focused on Dex, Con, Cha in that order. With the focus being on Swashbuckler and rogue tactics, the usual attraction of a Pact weapon is less important for this build- I still wanted to maximize Dex, and therefore hit with dex, have high sleight of hand, stealth for sneaking, etc. Part of this is because I do not intend to go beyond level 4 in Warlock. Thirsting blade does not work with Booming Blade, and that is a part of this character's design.
Cantrips Booming Blade and Magic Stone. Both synergize well with a rogue and sneak attack - booming blade adds direct damage to attacks after character level 5, as well as excelletn synergy with Fancy Footwork. Close to melee duel, sneak attack booming blade, free disengage, and back up taunting the target to chase you. If they move, the trigger the extra damage from Booming Blade. Magic Stone creates ammunition for a sling, which is eligible for sneak attack damage as well, making the attack deal magic damage as well, which is often useful. Eldritch Blast is not eligible for sneak attack. Still, taking Eldritch Blast can be flavorful for this character if you choose to go that way, and have her blast appear as a spectral cannon, or bow, or hand gun, etc.
Your pact boon here is very flexible, take whatever interests you. If you're in a party that craves more utility magic, Tome might be a good fit for cantrips and ritual casting via invocation. Chain is fun and flavorful, and with the Gift of the Ever-Living ones invocation can increase survivability. I like the Talisman, for its flexibility and buff to ability checks, plus the Rebuke of the Talisman invocation which gives you a use for your reaction - deal psychic damage equal to your proficiency bonus and push the target back 10' from the wearer of the talisman. Can free you up in a pinch, or protect your friend in combat. Blade is, again, less impactful on this build but not entirely useless. You could forgo a shield and dual wield. Swashbucklers are especially good at dual wielding, and the second hit gives you a second chance to land for sneak attack. Note this does not work with Booming Blade, though, as that is not an Attack action, but the Cast a Spell action. Still, especially against enemies with a high AC, it's good to have this option. Shadow Blade in one hand, Pact Blade in the other, and go in swinging both. Or, if you would rather have a pact weapon for ranged options instead of a sling and magic stone, for example, you can make a +1 dagger your pact weapon and throw it, or take the Improved Pact Weapon invocation and make a bow your pact weapon (though this interferes with wearing a shield). Conceptually, my character is a duelist with a rapier and shield, and I went with Talisman.
For invocations I have taken Armor of Shadows for free mage armor which, with a shield equipped and a 20 in Dex, gives me a 20 AC. This is as much a flavor choice as anything, though, as I like being armor-free. When I go to Warlock lvl 4, I may be swapping that out. The second invocation, though, is vital: Eldritch Mind. This grants advantage on Con saves to maintain your concentration on spells. Very important on a spell caster that is, by design, nearly always in melee range.
Four spells known are Mirror Image and Shield for increased survivability, though Armor of Agathys may also be a nice choice here depending on how often you are getting pinned down in melee. Again, Hex is less impressive on this build as the focus is on one attack per turn. It can be helpful for it's secondary benefits, though, such as Hex wisdom checks to give disadvantage to the target on perception, or strength/dex checks if you have a fellow melee party member who likes to grapple or use shield master to knock targets around. I have it, but I rarely actually use the Hex spell. The final spell I've chosen is Shadow Blade. This is where things can get really good.
Bonus action cast, summons a weapon in your open hand. Mechanically, this is a light, finesse, simple melee weapon with which you are proficient. This is a concentration spell, which is why Eldritch Mind is important, so you can keep your Shadow Blade up. It deals 2d8 psychic damage. Sneak attack deals bonus weapon damage, so using Shadow Blade changes your sneak attack damage type to psychic as well. Since it is a bonus action leveled spell, you can cast a cantrip as your action. Since it is a melee weapon you create, it is eligible for Booming Blade. It is possible, at level 8, to deal 2d8+dex psychic damage + 1d8 thunder + 3d6 psychic to a target, then freely disengage and back up. If they follow you on their turn, that triggers another 2d8 thunder damage.
Thanks for the detailed description and break down. This is a build that has also interested me. I would point out two things that I came across while looking at this. First, without the Warcaster feat, even with Pact of the Blade, you cannot cast Shield or Mirror Image (and many other Warlock spells) when carrying a weapon and shield as you will not have a hand free for the somatic component. If you pick up Warcaster, this is less of a problem, and you won't need Eldritch Mind. Your DM may allow 'drop the weapon-cast the spell-pick up the weapon' cheese for spells that require an action or bonus action to cast - I wouldn't - but probably not for spells cast as a reaction.
Also, your DM could rule that Booming Blade is incompatible with Shadow Blade, as Booming Blade requires a weapon of at least 1 sp value as a material component, which is used for the attack. Your DM may rule that a Shadow Blade does not have a value of 1 sp. It might be Booming Blade or Shadow Blade, but not both. That's the conclusion I reached.
Not trying to rain on your parade, just wanting to make sure that you were aware of potential pitfalls.
Rogue Warlock multiclass is a build that interest me even since Swashbuckler was released. When I do get a chance to try it out I am planning a little something outside the box. Gonna go V Human with the Crusher feat and go Genie Warlock (Dao) to trigger Crusher with my sneak powered Booming Blades. Not sure if I should use Eldritch Blast or carry a Hand Crossbow for ranged attacks though, leaning more towards a Hand Crossbow since I plan on boosting my DEX before CHA and Hand Crossbow can potentially trigger Sneak Attack. Ah who am I kidding I'll probably take Eldritch Blast as well lol.
Thanks for the detailed description and break down. This is a build that has also interested me. I would point out two things that I came across while looking at this. First, without the Warcaster feat, even with Pact of the Blade, you cannot cast Shield or Mirror Image (and many other Warlock spells) when carrying a weapon and shield as you will not have a hand free for the somatic component. If you pick up Warcaster, this is less of a problem, and you won't need Eldritch Mind. Your DM may allow 'drop the weapon-cast the spell-pick up the weapon' cheese for spells that require an action or bonus action to cast - I wouldn't - but probably not for spells cast as a reaction.
As the build was described by Cory, you are correct noob. But with 3 levels in warlock one could have the improved pact weapon invocation which would allow the pact weapon to act as a spellcasting focus.
Rogue Warlock multiclass is a build that interest me even since Swashbuckler was released. When I do get a chance to try it out I am planning a little something outside the box. Gonna go V Human with the Crusher feat and go Genie Warlock (Dao) to trigger Crusher with my sneak powered Booming Blades. Not sure if I should use Eldritch Blast or carry a Hand Crossbow for ranged attacks though, leaning more towards a Hand Crossbow since I plan on boosting my DEX before CHA and Hand Crossbow can potentially trigger Sneak Attack. Ah who am I kidding I'll probably take Eldritch Blast as well lol.
While I love crusher + BB, crusher seems redundant on a swashbuckler that already has a free way to disengage from enemies they hit with a booming blade. I'd go for a different subclass. It would be really cool if you could fit slasher on the build too because then you're pushing 5 feet and reducing speed by 10 with the same attack.
Since you don't seem to be going for a charisma based build I wouldn't bother with EB.
Thanks for the detailed description and break down. This is a build that has also interested me. I would point out two things that I came across while looking at this. First, without the Warcaster feat, even with Pact of the Blade, you cannot cast Shield or Mirror Image (and many other Warlock spells) when carrying a weapon and shield as you will not have a hand free for the somatic component. If you pick up Warcaster, this is less of a problem, and you won't need Eldritch Mind. Your DM may allow 'drop the weapon-cast the spell-pick up the weapon' cheese for spells that require an action or bonus action to cast - I wouldn't - but probably not for spells cast as a reaction.
As the build was described by Cory, you are correct noob. But with 3 levels in warlock one could have the improved pact weapon invocation which would allow the pact weapon to act as a spellcasting focus.
Rogue Warlock multiclass is a build that interest me even since Swashbuckler was released. When I do get a chance to try it out I am planning a little something outside the box. Gonna go V Human with the Crusher feat and go Genie Warlock (Dao) to trigger Crusher with my sneak powered Booming Blades. Not sure if I should use Eldritch Blast or carry a Hand Crossbow for ranged attacks though, leaning more towards a Hand Crossbow since I plan on boosting my DEX before CHA and Hand Crossbow can potentially trigger Sneak Attack. Ah who am I kidding I'll probably take Eldritch Blast as well lol.
While I love crusher + BB, crusher seems redundant on a swashbuckler that already has a free way to disengage from enemies they hit with a booming blade. I'd go for a different subclass. It would be really cool if you could fit slasher on the build too because then you're pushing 5 feet and reducing speed by 10 with the same attack.
Since you don't seem to be going for a charisma based build I wouldn't bother with EB.
The hand holding material components, which can be a spellcasting focus, can also be used for somatic components, if there are any. But if there are no material components but there are somatic components, (Shield, Mirror Image etc), you need a free hand or Warcaster.
The hand holding material components, which can be a spellcasting focus, can also be used for somatic components, if there are any. But if there are no material components but there are somatic components, (Shield, Mirror Image etc), you need a free hand or Warcaster.
This is not true.
Material (M)
Casting some spells requires particular objects, specified in parentheses in the component entry. A character can use a component pouch or a spellcasting focus (found in chapter 5, “Equipment”) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell.
If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell.
A spellcaster must have a hand free to access a spell's material components — or to hold a spellcasting focus — but it can be the same hand that he or she uses to perform somatic components.
The spellcasting focus works in place of the components specified for a spell. All of them. There is no qualifier that says this only happens if the spell has a material component.
Didn't catch the 1sp from the TCoE errata to Booming Blade, that's a small change that impacts many, many users of that spell. Odd qualifier to add. Can't really BB with either Shadow Blade OR a pact weapon, then, if its a magic weapon which carries no gold value. Jeez.
With Shadow Blade, if you maintain concentration, it's a bonus action to re-summon. So I had flavored as the shadow being blasted apart by booming blade, mechanically dropping the weapon after I hit with it, and then backing away from the target. Warcaster is the plan, though. Much more elegant, and has other benefits, including keeping a weapon for potential opportunity attacks, freeing my bonus action, etc. Until I get there, this shadow burst has been the MO.
Though, as you say, with the change to booming blade my MO has apparently been illegal anyway.
The rules you quote apply to material components. If the spell does not require material components, the rules for material components do not apply. The rule for somatic components reads:
Somatic (S)
Spellcasting gestures might include a forceful gesticulation or an intricate set of gestures. If a spell requires a somatic component, the caster must have free use of at least one hand to perform these gestures.
If it were otherwise, Warcaster would be much less useful and classes which can use weapons or shields as spell cast focuses are further advantaged over others.
Rollback Post to RevisionRollBack
To post a comment, please login or register a new account.
So, I've wanted to do this for a while ever since Swashbuckler came out, but I never got the chance until now. Unfortunately, I always get stuck on how many levels I want to put into what, and since these forums have helped me in the past with this sort of thing, I might as well ask again!
The character concept is Lokhir Felheart inspired; a dual-wielding pirate lord with skills as a duelist whose prowess is further enhanced by magic.
I plan to pop him in at Level 5 at Rogue 3 / Warlock 2 as a prepared replacement for another character who I have.
So, does anyone have any thoughts or ideas? How should I spec him for future levels?
I am no expert of this Lokhir guy, but from an optimization point of view assuming you want your physical weapons to be your main attacks, you want at least 5 levels of warlock for an extra attack. Since rogue gets their most powerful feature at level 11 I would say Swashbuckler 11/Hexblade 5 is a good foundation. What you do with the last 4 levels is a lot less obvious. One synergistic version would be Swashbuckler 12/Hexblade5/Battlemaster 4.
If you take the see-through-darkness Invocation make sure to have darkness as one of your spells, and a melee char with counterspell is never a bad thing.
I’ve been theory crafting a rogue/lock myself, though what I have a little different but with what you have in mind I might suggest going pact of the blade and taking the thirsting blade and Eldritch smite invocations when you reach level 5 warlock that way with duel wielding you’d have a total of 3 attacks per round and throw the hex spell into the mix you’ll be adding an additional 1d6 per hit with the option to add more damage if you so choose. Now if you also want look at the shadow blade spell as it might also be something you’d be interested in. Since you are going to be melee if might be a good idea to max out con and take the tough feat so your character doesn’t have a glass jaw and can take some damage with our worrying about going down.(I’m building a 4fiend lock/3 trickster with a 16 con with tough average hit points would be 75 at 7th)
edit: I forgot to also mention with hex blade you can have both your hex blade and pact weapon at the same time, and your pact weapon also receive the same benefits with char to hit and damage
Not aware of thr character your mentioned, but i have some suggestions for hex/swash and pirate themes
1. You dont get two weapon fighting style, so if its not a core character concept i would personally shift to using booming blade with either a scimitar or rapier. Dual wielding does give you a second chance to hit, but later on swashbuckler gets that anyway. Booming blade is very powerful on a swashbuckler because you get the free disengage, meaning you can still dash away or do other things with your cunning action.
2. Dual wielding doesnt work with hex warrior. Of you use a single handed weapon you can go all in on your charisma to be the most suave pirate you can be, and rely on medium armor with 14 dex for protection.
3. If you do go further in warlock, you can see if your dm will allow the imp familiar to turn into a parrot instead of a raven.
4. Mask of many faces + expertise + friends cantrip is a very powerful combination. If you play it right you get the target mad at either a random person or at your enemy while still getting information or favors. Your other invocation could be misty visons for easy concealment, or maybe devil sight or whatever else you fancy.
I've been playing a swashbuckler through a long campaign up through level 12. Thirteen, I wanted something different. Talked my DM into my character making a dark pact for hexblade multiclass. Through my adventures, I've got 20 Dex, 18 Cha, a+2 Cutlass (rapier reskin), magic initiate for find familiar and booming blade. I dip into hexblade and get a shield and mage armor cause I'm a bit squishy. Devil sight and darkness spell. I'm attacking with +12 to hit. Doing 3d8+6d6+7 damage on one hit. With advantage in the darkness. Free to move away, and 3d8 if they move. She hits like a truck. Not many HP, but a cloak of protection helps make me hard to hit. I love it.
I’ve been theory crafting a 15 swashbuckler/ 5 hex blade scourge aasimar. I chose that mix because I wanted the 8d6 sneak attacks, access to 3rd lvl spells, second stage cantrips, being able to focus cha and con with only 14 dex, and 3 invocations specifically. Booming blade and eldritch blast are core, with a third cantrip of choice. For invocations I decided on grasp of hadar, agonizing blast, and lance of lethargy. You could take the added attack but it adds pretty little damage when not using shadow blade. The last option I would consider is eldritch smite to get even more 1 shot potential, but I wanted my character to be better at chasing people down so I went with the additional cc. Booming blade lets you move for free or damage them after you pull and slow them with no save. Hardcore duel potential with scourge for added damage and aoe.
Currently playing a Halfling Swashbuckler / HexChain and it is darn effective. I am the front-line fighter and chose to use a shield as well. I have a lot of in game versatility and can hold the line. I picked up booming blade, shield, and absorb elements for a well rounded defensive strategy. Eldritch Blast enables me to have a reliable ranged option if needed, but I usually can get within range and rapier the heck out of any enemy in high flying fashion.
I find the Chain option adds a silly amount of character versatility and keeps me from being a one trick pony. Keeping an invisible ally that can provide you with the help action every round is also a massive boon to your one attack. My familiar is usually invisible and flying directly above my position ready to cause annoying distractions to my opponent like positioning rocks under their footing, bumping into their backs when they are maneuvering, or wafting a foul breeze into their faces to help. The scouting and general helping hand an advanced familiar can offer in and out of combat is only limited by the imagination of the player and allowances granted by the GM. It is a class feature after all, and should be treated like one instead of just a spell.
IMHO, Earthdawn is still the best fantasy realm, Shadowrun is the best Sci-Fi realm, and Dark Sun is the best D&D realm.
Thirsting Blade, which is the Warlock equivalent of Extra Attack, only works with Pact Weapons (and requires five levels in Warlock).
If you do have five levels in Warlock you can take Pact of the Blade, summon one scimitar as your main hand weapon and keep the regular scimitar as your off-hand weapon, however that's really going all in on Warlock. It's why I've come to regard multi-classing as a bit of a trap (unless it's something like a single level in Hexblade for a College of Swords Bard).
Just fyi if you didn't know, booming blade doesn't activate unless they willingly leave your melee range. You'll still get your on hit bonus though, of course.
Unfortunately hexblades don't lend themselves well to dual wielding because the cha bonus can only be applied to one weapon. However, if you want to dish out lots of attacks you could go for a double-bladed scimitar through the pact of the blade boon. With the corresponding feat this counts as a finesse weapon, letting you deal sneak attacks and functionally be dual wielding.
just so you know the cantrip scaling works with your total level, not your level in the specific class. So you'd actually have fifth stage cantrips with that build, cantrips are one of the few things to scale with total level.
Cantrips and Proficiency Bonuses.
For those coming across this now, here is my experience playing Swashbuckler/Hexblade. For my concept, the character is more Swashbuckler focused than Warlock focused, so I at lvl 8 I am Swashbuckler 5/Hexblade 3. I went with a variant Tiefling, Devil's Tongue, for flavorful spells: Vicious Mockery, Charm Person, Enthrall are all great on a dashing Swashbuckler type. Stats for this character I focused on Dex, Con, Cha in that order. With the focus being on Swashbuckler and rogue tactics, the usual attraction of a Pact weapon is less important for this build- I still wanted to maximize Dex, and therefore hit with dex, have high sleight of hand, stealth for sneaking, etc. Part of this is because I do not intend to go beyond level 4 in Warlock. Thirsting blade does not work with Booming Blade, and that is a part of this character's design.
Cantrips Booming Blade and Magic Stone. Both synergize well with a rogue and sneak attack - booming blade adds direct damage to attacks after character level 5, as well as excelletn synergy with Fancy Footwork. Close to melee duel, sneak attack booming blade, free disengage, and back up taunting the target to chase you. If they move, the trigger the extra damage from Booming Blade. Magic Stone creates ammunition for a sling, which is eligible for sneak attack damage as well, making the attack deal magic damage as well, which is often useful. Eldritch Blast is not eligible for sneak attack. Still, taking Eldritch Blast can be flavorful for this character if you choose to go that way, and have her blast appear as a spectral cannon, or bow, or hand gun, etc.
Your pact boon here is very flexible, take whatever interests you. If you're in a party that craves more utility magic, Tome might be a good fit for cantrips and ritual casting via invocation. Chain is fun and flavorful, and with the Gift of the Ever-Living ones invocation can increase survivability. I like the Talisman, for its flexibility and buff to ability checks, plus the Rebuke of the Talisman invocation which gives you a use for your reaction - deal psychic damage equal to your proficiency bonus and push the target back 10' from the wearer of the talisman. Can free you up in a pinch, or protect your friend in combat. Blade is, again, less impactful on this build but not entirely useless. You could forgo a shield and dual wield. Swashbucklers are especially good at dual wielding, and the second hit gives you a second chance to land for sneak attack. Note this does not work with Booming Blade, though, as that is not an Attack action, but the Cast a Spell action. Still, especially against enemies with a high AC, it's good to have this option. Shadow Blade in one hand, Pact Blade in the other, and go in swinging both. Or, if you would rather have a pact weapon for ranged options instead of a sling and magic stone, for example, you can make a +1 dagger your pact weapon and throw it, or take the Improved Pact Weapon invocation and make a bow your pact weapon (though this interferes with wearing a shield). Conceptually, my character is a duelist with a rapier and shield, and I went with Talisman.
For invocations I have taken Armor of Shadows for free mage armor which, with a shield equipped and a 20 in Dex, gives me a 20 AC. This is as much a flavor choice as anything, though, as I like being armor-free. When I go to Warlock lvl 4, I may be swapping that out. The second invocation, though, is vital: Eldritch Mind. This grants advantage on Con saves to maintain your concentration on spells. Very important on a spell caster that is, by design, nearly always in melee range.
Four spells known are Mirror Image and Shield for increased survivability, though Armor of Agathys may also be a nice choice here depending on how often you are getting pinned down in melee. Again, Hex is less impressive on this build as the focus is on one attack per turn. It can be helpful for it's secondary benefits, though, such as Hex wisdom checks to give disadvantage to the target on perception, or strength/dex checks if you have a fellow melee party member who likes to grapple or use shield master to knock targets around. I have it, but I rarely actually use the Hex spell. The final spell I've chosen is Shadow Blade. This is where things can get really good.
Bonus action cast, summons a weapon in your open hand. Mechanically, this is a light, finesse, simple melee weapon with which you are proficient. This is a concentration spell, which is why Eldritch Mind is important, so you can keep your Shadow Blade up. It deals 2d8 psychic damage. Sneak attack deals bonus weapon damage, so using Shadow Blade changes your sneak attack damage type to psychic as well. Since it is a bonus action leveled spell, you can cast a cantrip as your action. Since it is a melee weapon you create, it is eligible for Booming Blade. It is possible, at level 8, to deal 2d8+dex psychic damage + 1d8 thunder + 3d6 psychic to a target, then freely disengage and back up. If they follow you on their turn, that triggers another 2d8 thunder damage.
@CoryRothwell,
Thanks for the detailed description and break down. This is a build that has also interested me. I would point out two things that I came across while looking at this. First, without the Warcaster feat, even with Pact of the Blade, you cannot cast Shield or Mirror Image (and many other Warlock spells) when carrying a weapon and shield as you will not have a hand free for the somatic component. If you pick up Warcaster, this is less of a problem, and you won't need Eldritch Mind. Your DM may allow 'drop the weapon-cast the spell-pick up the weapon' cheese for spells that require an action or bonus action to cast - I wouldn't - but probably not for spells cast as a reaction.
Also, your DM could rule that Booming Blade is incompatible with Shadow Blade, as Booming Blade requires a weapon of at least 1 sp value as a material component, which is used for the attack. Your DM may rule that a Shadow Blade does not have a value of 1 sp. It might be Booming Blade or Shadow Blade, but not both. That's the conclusion I reached.
Not trying to rain on your parade, just wanting to make sure that you were aware of potential pitfalls.
Rogue Warlock multiclass is a build that interest me even since Swashbuckler was released. When I do get a chance to try it out I am planning a little something outside the box. Gonna go V Human with the Crusher feat and go Genie Warlock (Dao) to trigger Crusher with my sneak powered Booming Blades. Not sure if I should use Eldritch Blast or carry a Hand Crossbow for ranged attacks though, leaning more towards a Hand Crossbow since I plan on boosting my DEX before CHA and Hand Crossbow can potentially trigger Sneak Attack. Ah who am I kidding I'll probably take Eldritch Blast as well lol.
As the build was described by Cory, you are correct noob. But with 3 levels in warlock one could have the improved pact weapon invocation which would allow the pact weapon to act as a spellcasting focus.
While I love crusher + BB, crusher seems redundant on a swashbuckler that already has a free way to disengage from enemies they hit with a booming blade. I'd go for a different subclass. It would be really cool if you could fit slasher on the build too because then you're pushing 5 feet and reducing speed by 10 with the same attack.
Since you don't seem to be going for a charisma based build I wouldn't bother with EB.
The hand holding material components, which can be a spellcasting focus, can also be used for somatic components, if there are any. But if there are no material components but there are somatic components, (Shield, Mirror Image etc), you need a free hand or Warcaster.
This is not true.
The spellcasting focus works in place of the components specified for a spell. All of them. There is no qualifier that says this only happens if the spell has a material component.
Didn't catch the 1sp from the TCoE errata to Booming Blade, that's a small change that impacts many, many users of that spell. Odd qualifier to add. Can't really BB with either Shadow Blade OR a pact weapon, then, if its a magic weapon which carries no gold value. Jeez.
With Shadow Blade, if you maintain concentration, it's a bonus action to re-summon. So I had flavored as the shadow being blasted apart by booming blade, mechanically dropping the weapon after I hit with it, and then backing away from the target. Warcaster is the plan, though. Much more elegant, and has other benefits, including keeping a weapon for potential opportunity attacks, freeing my bonus action, etc. Until I get there, this shadow burst has been the MO.
Though, as you say, with the change to booming blade my MO has apparently been illegal anyway.
The rules you quote apply to material components. If the spell does not require material components, the rules for material components do not apply. The rule for somatic components reads:
Somatic (S)
Spellcasting gestures might include a forceful gesticulation or an intricate set of gestures. If a spell requires a somatic component, the caster must have free use of at least one hand to perform these gestures.
There is a 30 page debate you can read here.
If it were otherwise, Warcaster would be much less useful and classes which can use weapons or shields as spell cast focuses are further advantaged over others.