mellored
Legend
Getting you your 20d6 without a "rogue only" item or feat.Not sure what you're trying to accomplish.
Not sure why you see how a weapon that isn't locked to just rogues as a problem.That they are equally applicable to every weapon user is not the solution. It is the problem.
Do you want d8, or 20d6?I want to add an extra d8 to rogue damage on average.
Sneak Attack is once per turn.I'm trying to satisfy the playstyle where your sneak attack gets scary but you otherwise remain unremarkable.
The rules already allow for the possibility you deal sneak damage twice or more during a turn.
Unless your talking about haste + ready action.
5d6+sneak attack is more than 1d6+sneak attack.Helping the rogue in general would defeat this goal.
IMO, that is more scary.
So I still don't understand what your saying.
But here's a few more ideas.
Dagger of Death
This dagger comes with 10 charges. It regains 1d6 charges at midnight.
When you make an attack roll and roll an 19 on the d20 you can expend 1 charge, if it was an 18 you can expend 2 charges, a 17 cost 3 charges, a 16 cost 4 charges, and a 15 cost 5 charges.
If you do, the attack become a critical hit.
Dagger of more Death
When you deal damage with this dagger, you can reroll any damage dice. You must use the new results.
Dagger of Unforseen Assault
When you hit a creature while you have advantage, or that is adjacent to an ally, you deal an extra 2d6 damage.
Cut throat.
Make sneak attack scary again. (Might be a bit OP).
Level 3: Ruthless
increase sneak attack dice to a d8's.
Level 9: twist the knife.
Immediately after hitting a target that you will deal sneak attack damage to, you can spend a bonus action to increase all the sneak attack dice to d10's
Level 13: slit the throat
You gain the following cunning strike options.
(2d6) The target is unable to make any verbal noises until the end of your next turn.
Level 17:
Go for the jugular
If the target fails their save against slit the throat, increase your sneak attack dice to a d10's, or d12's if you use twist the knife.