Dex battlemaster multiclass?

[Asuryan9]

So I have a dex battlemaster fighter. Air genasi. He will level to 5 after our next game. I want my second attack. I was thinking of multiclassing into rogue after that for a few levels.
I'll get some more skill proficiency.
Expertise.
Proficiency in thieves tools (we have no rogue, no one to pick locks).
If I stay for 3 levels I'll get 2d6 sneak attack and assassination.

With my battlemaster I can give myself advantage 4 times per short rest with superiority dice. Also have advantage on guys who haven't acted yet. Which at +5 initiative I often go first or close to it.

Plus I am pretty often beside the half orc barb so I will get sneak attack pretty regularly.

Air genasi battlemaster.
Str- 10
Dex- 20
Con- 16
Int- 11
Wis- 14
Cha- 8

Anyone have any opinions or ideas?

[Easy_Lee]

Battlemaster into Assassin is solid. People usually do this on archer builds, but it should work regardless.

What is your fighting style and weapon?

[Asuryan9]

Dueling fighting style and I have a +1 dagger from pota. Makes no sound and radiates light in 10 feet when I want.

I was using a rapier but we came across enemies that needed magic or silvered weapons to take full damage so I figured the average damage reduction of 1 point was worth using a magic weapon,+1 to hit and I hate the image of using a rapier hahah

[Specter]

I believe you can get more out of Swashbuckler than out of Assassin.

[Asuryan9]

I believe you can get more out of Swashbuckler than out of Assassin.

Eh the advantage all the time is nice, but the charisma usage is wasted.
I feel like I will get advantage enough, or have enemies next to one of my other players enough that I'll have a steady stream of sneak attack damage. I dont want to pass up on the damage I can get if we get a surprise round.

[Joe the Rat]

I dont want to pass up on the damage I can get if we get a surprise round.

Now that you're 5th level, How often has your party gotten surprise rounds? If you guys are solid on ambushing, then definitely assassin. If you guys barely get the drop... advantage on "flat-footed" is still handy, but you already have means to get advantage / process sneak attack. It is a solid choice.
let me throw a couple more at you:
Thief: If you aren't using a shield, duelist means your preferred fighting style is one hand free. Thief gives you a LOT of uses for that free hand.
Mastermind: Turn your Battlemaster into a pocket Warlord. When you aren't disengaging, you can use that bonus action to Help anyone within 30 feet. You can give Advantage to any ally within 30 feet. Like Assassin, it provides those "spy tool" proficiencies - with a heavier focus on infiltration.

There's also Arcane Trickster, but it doesn't fit your current MO as well. Invisible mage hand and ranged lockpicking are handy, and could play off of your "I'm part air" schtick.

[Asuryan9]

Now that you're 5th level, How often has your party gotten surprise rounds? If you guys are solid on ambushing, then definitely assassin. If you guys barely get the drop... advantage on "flat-footed" is still handy, but you already have means to get advantage / process sneak attack. It is a solid choice.
let me throw a couple more at you:
Thief: If you aren't using a shield, duelist means your preferred fighting style is one hand free. Thief gives you a LOT of uses for that free hand.
Mastermind: Turn your Battlemaster into a pocket Warlord. When you aren't disengaging, you can use that bonus action to Help anyone within 30 feet. You can give Advantage to any ally within 30 feet. Like Assassin, it provides those "spy tool" proficiencies - with a heavier focus on infiltration.

There's also Arcane Trickster, but it doesn't fit your current MO as well. Invisible mage hand and ranged lockpicking are handy, and could play off of your "I'm part air" schtick.

Honestly? We get a sneak attack round pretty often if we are trying to do it. Which is what made me think assassin right away.
I do use a shield, cool idea to go thief if I wasnt using a shield tho.
Hmmm I am going to have to look into mastermind for sure. The only other melee class in our party is a barb and he attacks recklessly every time. I dont think, even if I helped and gave him advantage, that he wouldnt attack recklessly. He just likes to do it lol. So the assassin might be better for me. Going to think about it for sure tho.