So, I'm playing a level 5 Fighter Battle Master. I'm thinking about multiclassing with Rogue, for the Sneak Attack. I'll use a rapier, since it has 1d8 damage and acuity. At level 5/1 (Fighter/Rogue)
I want to do a combo like this (considering I hit every attack):
Use my basic action to attack; Proc Extra Attack to do it twice; on my first hit I'll use the "Trip Attack" maneuver to add extra damage and cause a Strength saving throw
As he fails the throw, he will fall prone; Every attack after that is with Advantage; I'll finish my first Attack action with the Extra one at advantage
Then, I'll use "Action Surge" and gain a extra Action; Then use this action to Attack again; This time, since I have advantage on both the attacks, I'll use "Sneak Attack" to add 1d6 to each of "Extra Attack" attacks
Dealing in total: 2d8 on the first attack (Trip Attack), 1d8 on the second, 1d8 + 1d6 on the third and forth attacks.
A total of: 5d8 + 2d6
Can this be done?
Seeing as you can use Sneak Attack once per turn to add 1d6 to the DMG roll of an attack you hit. Since my attack action allow me to attack twice, would that work?