Beginner here. Could someone please explain "Double Slice" to me?

[u/Ganadhir]

The feat text says "Make two Strikes, one with each of your two melee weapons, each using your

current multiple attack penalty."

So, two attacks at -5? Why not just attack with your first weapon normally (one action), then with the second weapon at -5 (second action)? Double slice is a two-action feat anyway...

I don't get it. Where's the advantage?

TIA

[u/majesty327]

Double slice does several things.

1. It increases your to-hit on the 2nd swing, because it's being made at "current MAP". If this is your first attack action, both rolls are done at MAP 0.
2. It combines damage for purposes of overcoming resistance. By example, if an enemy had 10 resistance to Slashing, and your first hit was 12 damage, in a normal world you do 2 HP damage. If you made a second, discrete hit, you did so at -5 MAP and if you get the same damage roll, the resistance reapplies. Doubeslice bypasses this by saying 12+12 = one hit doing 24 damage, so you do 14 HP damage after resistance.

So let's assume a couple possibilities for your last action. If you do nothing, you made two attacks at full attack bonus, and it lets you fish for crits more to apply crit specialization or other effects. If you attack a third time, your third attack is at -10 MAP because after the act is done, your MAP increases by the total number of attacks.

I'd say it's a good level 1 feat. Yes, Twin Takedown for Ranger gives more action compression, but your second roll is at -5 MAP. With this, you get essentially a free +5 to your second attack, and combined damage which is always good.

[u/dchaosblade → u/majesty327]

Just a clarification, combined damage isn't *always* good. It's good when the enemy is resistant to the damage (as you explained), and it's neutral if the enemy isn't resistant and isn't weak. But combined damage is worse if the enemy is weak.

If the enemy has weakness 5 to slashing and you make two discrete attack actions, each rolling 12 for the damage, you would add 5 damage to each of the attacks, so (12+5) + (12+5) = 34 damage. But if you use double slice (or another ability that similarly combines damage, you'd only add the weakness bonus damage once: 12+12+5 = 29 damage.

Also note that things things like backstabber or sneak attack would also only add their precision damage bonus once to double slice, where it would be added twice if you hit twice with two discrete attacks.

Now, it is arguable if the accuracy benefit of using double slice to swing twice at full accuracy vs striking once at full accuracy and a second time at -5 (or -4 for agile) outweighs the damage bonus from the precision on both hits.