Hey all, was doing this math and had a significantly different outcome and I could use some help from you math Geniuses. 

So its 2nd level Rogue assassin/ 3d level warrior Battlemaster (5 lvls total) vs  2nd level Rogue Assassin/ 3d level Ranger Gloom stalker and we talking melee here. I did this set up with four turns to see potential max damages and found one to be far superior to the other and wanted to make sure I didn't do something commpletely wrong. I am new to 5e and played years and years (and years) ago with D&D, AD&D, and AD&D 2nd edition. so...

Test vs 10 AC creature

Raven- 

Classes: Assassin 2 lvls- Battle Master 3 levels. 

Weapon: Rapier 

Turn 1

• Sneak attack+Weapons DMG+dmg Bonus= 6+8+6=20
• Bonus action Feint (1 sup die to dmg plus advantage) to Action surge= WP dmg+dmg Bonus+sup die bonus = 8+6+8= 22
• Total 42points of dmg

Turn 2

• Feint (2 sup die) to advantage = wp dmg+dmg bonus+sneak att bonus+superiority die bonus = 8+6+6+8= 28

Turn 3

• Feint (2 sup die) to advantage = wp dmg+dmg bonus+sneak att bonus+superiority die bonus = 8+6+6+8= 28

Turn 4

• Feint (2 sup die) to advantage = wp dmg+dmg bonus+sneak att bonus+superiority die bonus = 8+6+6+8= 28

Total:126 points of MAX dmg

Raeven

Classes: Assassin 2 level’s, Gloom Stalker 3 levels

Weapon: 2 Short Swords 

Turn 1

• Bonus action Hunters mark 1d6
• Attack + Dmg bonus +sneak attack+HM = 6+4+6+6=22
• Dreaded Ambusher Attack+ Dmg bonus+HM = 6+4+6=16

Total 38

Turn 2

• Attack- + Dmg bonus +sneak attack+HM = 6+4+6+6=22
• Bonus action off hand attack + hunters Mark+ Dmg Bonus= 6+6+4=16

Total 38

Turn 3

• Attack- + Dmg bonus +sneak attack+HM = 6+4+6+6=22
• Bonus action off hand attack + hunters Mark+ Dmg Bonus= 6+6+4=16

Total 38

Turn 4

• Attack- + Dmg bonus +sneak attack+HM = 6+4+6+6=22
• Bonus action off hand attack + hunters Mark+ Dmg Bonus= 6+6+4=16

Total 38

TOTAL: 152 points of MAX dmg

How does this look? I know I have other options than feinting for battlemaster but they mostly give advantage which I already have, however feinting adds dmg which is why I am using it even if I already have advantage with another melee within 5ft.

any advice is appreciated. TY in advance!

You do not get sneak attack damage multiple times turn 1. Action surge gives you another action but it's the same turn.

Also your attribute bonus should be +3 assuming a 16 dex(+6 is not possible since that requires 22dex which cannot be reached) if AB stands for attack bonus the +6(16dex + 3 proficiency) is only a to hit bonus.

Edit: I'm less familiar with the ranger specific side, so someone else will have to check that side.

What is "AB bonus"? Is that ability bonus? Why is it always 6?

Arrgh your both right. It's actually plus 4 for short sword. plus 6 for rapier. BOth have 18 dex. I built them on the editor so it's all legit.

assassin battlemaster 

Quote from Noksa >>

You do not get sneak attack damage multiple times turn 1. Action surge gives you another action but it's the same turn.

Also your attribute bonus should be +3 assuming a 16 dex(+6 is not possible since that requires 22dex which cannot be reached) if AB stands for attack bonus the +6(16dex + 3 proficiency) is only a to hit bonus.

Edit: I'm less familiar with the ranger specific side, so someone else will have to check that side.

 Your right I removed that second sneak attack thank you! and actually, I just noticed I added it to all off hand attacks as well. arrgh!! I'm so bad at this. I did the characters on DnD beyond's character builder with 18 Dex and that's what is coming up with all profeciencies and what not included. +6 for rapier (duelist style), plus+4 for Short sword

OK, I made corrections based on your comments and understanding some mistakes. Any other things you can catch please let me know. also, I cleaned it up so it's easier to read. 

THanks everyone!

Is this character gonna be leveling up? Level 2 rogue isn’t an assassin yet and isn’t providing much compared to extra attack for fighter or ranger and ability score boost. 

Quote from Atomic_Robo >>

Is this character gonna be leveling up? Level 2 rogue isn’t an assassin yet and isn’t providing much compared to extra attack for fighter or ranger and ability score boost. 

 Yea. The campaign we are doing now takes us to level 5 so i am only planning out the 5 levels. After that, when we hit another campaign, I will just raise up rogue all the way to 17.

Math looks about right now, I just question the value of comparing max damage under ideal circumstances. But you do you.

Quote from pangurjan >>

Math looks about right now, I just question the value of comparing max damage under ideal circumstances. But you do you.

 Yea I am still keeping an eye on chance to hit. TY

Quote from Rationale01 >>

Quote from pangurjan >>

Math looks about right now, I just question the value of comparing max damage under ideal circumstances. But you do you.

 Yea I am still keeping an eye on chance to hit. TY

 The real difference is that the Battlemaster can force advantage without needing any help, which the Gloomstalker can't. Ignoring that and only looking at ideal damage potential is like comparing wizards to sorcerers without taking metamagic into account.

One other thing I'd recommend is using the average damage for die rolls. The point of this being that the average of 4d6 is 14 damage, while the average of (1d6+6) + (1d6+6) would be 19 damage. I'm not sure that's going to change your relative values in this instance (since both builds are inflating the effect of extra dice), but if you're ever comparing build with different numbers of attacks, it becomes fairly important.

The first 5 levels are pretty important.  I'd just pick a class and stick with it through level 5.

For that  17 adventure upcoming, Gloomstalker 5 / Assassin X is a good combo.  3 Attacks that all crit on a surprise round is pretty cool.