So im not sure if this is how the math works, so if im wrong please tell me, all input is welcome. im a rogue assassin (level 5) / fighter (level2) character, and i use two weapon fighting style (from the fighter) to weild a rapier and a +2 dagger with 20 dex (+5 mod. rolled an 18 and then did a plus 2 from, human varant). Plus, i have the feat Alert which gives me a +5 to initiative that i took from the human variant. I also have a cape that basically makes me Nightclawer from the Xmen where i can teleport up to 500 feet, once a day as a free action. my question is this: if i teleport behind a creatue and sneak attack (hed be surprised, since one moment i would be in one spot some amount of distance away, and the very next moment im attacking him from behind, so automatic crits would happen) with both weapons and then action surge would my damage end up being a max of 94?
my rapier would be doing 13 (max damage of 1d8 plus dex mod) plus a 1d8 ( max of 8) for the crit and then doing it again for the action surge. so max of 42 with rapier.
then my dagger would be doing 11 (max damage 1d4+2 plus dex mod) plus another 1d4+2 for the crit and then doing it again for the action surge. so far max of 34 with dagger.
then to deal with the sneak attack (3d6 at level 5 rogue). So that would be 18 max damage for that. 18+34+42 would end up being 94 damage.
Right?
also, pardon my grammer.
sneak attack is 1/turn.
critical is rolling the dice twice, not max.
assassin works on all attacks on your first turn, so they are all crits.
you cannot TWF with a rapier + dagger, unless you have the feat (in which case you can use 2 rapiers). shorts swords + dagger would work though.
So...
action: 1d4+5+2 (+1d4 crit)
action surge: 1d4+5+2 (+1d4 crit)
TWF: 1d6 +5 (+1d6 crit)
sneak attack 3d6 (+3d6 crit).
= 4d4 + 8d6+19
= 57 on average.
If you happen to roll max on all 12 of your dice (which is super extrodinaraly unlikey)...
83 damage.
mellored wrote:
action surge does not give you another bonus action.
and the houserule is fine, assuming it applies both ways. it makes the game a bit deadlier for both sides.
OK your first incorrect assumption is that your target will be surprised if you teleport behind them. Surprise has very specific requirements, the first being that the target is unaware of you. If they have seen you, it doesn't matter if you teleport behind them or not - they are not surprised. Surprise only happens in the first round of combat. To gain surprise, you have to essentially ambush the target and hope they don't spot you before you trigger the ambush.
Other methods which can cause surprise on both sides is if two parties step around the corner at the same time and neither was aware of the other before hand. Ultimately, it is the DMs call if one or both sides can be surprised, and who (if anyone) is surprised. (see surprise in the PHB)
Your DM might give you advantage on your attack due to how sudden it is, but they are under no obligation to do so. This would be a DM call.
Secondly, I would not base your calculations off your maximum damage potential. Those in char op prefer to base it on your expected DPR (this is your mean average once all factors are considered). While variations will occur from combat to combat, over the course of a character's career, you can expect to deal X damage with Y combo.
A rapier deals 1d8 (4.5) damage. Your +2 dagger deals 1d4+2 (4.5) damage. As we don't know the target number, I will simply assume an average AC of 15. You are also talking about +5 dex mod based on your damage calculations, so that means +8 to hit (+3 proficiency, +5 dex). This gives you damage values of 9.5 with your rapier and 7.5 with your dagger (assuming TWF fighting style).
Your math would be as follows (I am ignoring surprise as this is DM fiat) - keep in mind I am not a math major, and don't know the mathematical shortcuts to calculate this.
- Hit chance: AC 15-8 means you will hit on a 7 or above and crit on a 20. This gives us a 70% hit chance (65% hit, 5% crit) on each attack.
- Action (rapier): 9.5 x 65% (hit) + 14 x 5% (crit) = 6.175 + 0.7 or 6.875 DPR
- Bonus Action (dagger): 9.5 x 65% (hit) + 12 x 5% (crit) = 6.175+0.6 or 6.775 DPR
Sneak Attack (no action surge)
- SA hit chance: 70% + (70% x 30%) = 70% + 21%, or a 91% chance of SA (that doesn't look right, can someone confirm this), assuming you either have advantage or an ally adjacent to the target.
- SA DPR: 3d6 (10.5) x 91% = 9.55
Sneak Attack (action surge)
- SA hit chance: 91% + (30% x21%) = 91.063
- SA DPR: 10.5 x 91.063 = 9.561 - negligable difference.
DPR
- Total DPR (without SA): 6.875+6.775 = 13.65 vs. AC 15
- Total DPR (with SA): 13.65+9.55 = 23.2 vs. AC 15.
- Total DPR (Action surge, no SA): 6.875 + 6.875 + 6.775 = 20.525 vs AC 15
- Total DPR (Action surge + SA): 20.525 + 9.561 = 30.086
You will deal an average of 30 damage on your nova round (action surge) and 23.5 damage on your off-nova rounds against AC15 assuming you gain SA.
Kalani wrote:
I should have clarified - I meant not aware of an impending attack. Your example is 100% accurate. If you attack suddenly in a peaceful social encounter, that too can warrent surprise. In such a situation however, whether the character is surprised or not comes down to your opposed Deception (passive Insight) instead of Stealth (passive perception) in the case of an ambush.
In either situation, if the target was actively looking for deception or was searching the area, surprise would be determined by opposed Deception (Insight) or Stealth (perception) checks instead. Passive checks are only used if they aren't purposefully looking for deception/trouble.
Kalani wrote:
Max damage crits heavily work against the party. Thats a pretty deadly house rule.
You need a feat to dual wield a rapier with any other weapon, since its not a light weapon.
You only can deal sneak attack dice once per turn. Action surge doesn't change this.
Your game rules seem way more Monty Haul than the 5e i am used to. 7th level characters dont normally have a 20 stat, and very rare and legendary magic items are supposed to be rare. So it sounds like there is a lot of hand waving going on.
Byakugan01 wrote:
Nothisispatryck wrote:
Barimen wrote:
Noctaem wrote:
Noctaem is just making a distinction between "dual wielding" which is holding a weapon in each hand, and "two weapon fighting" which is attacking with a weapon in each hand. As he says, anyone can hold two rapiers and attack with just one of them.
But it's a bit pedantic, IMO 
jaelis wrote:
Barimen wrote: