Help me figure out the interaction between the fatal trait and a striking rune

[eventyret]

I'm trying to figure out what the correct damage calculation is when you crit with a weapon with the fatal trait and a striking rune. The fatal trait: "The fatal trait includes a die size. On a critical hit, the weapon’s damage die increases to that die size instead of the normal die size, and the weapon adds one additional damage die of the listed size." the pick is one example of a weapon with this trait (1d10 fatal, 1d6 regular). The rules for damage state that "Each weapon lists the damage die used for its damage roll. A standard weapon deals one die of damage, but a magical striking rune can increase the number of dice rolled, as can some special actions and spells. These additional dice use the same die size as the weapon or unarmed attack's normal damage die". My confusion comes from the use of the word "normal" in that sentence. The text from fatal would imply that for the pick, the d6 is the normal damage die and on a crit the damage die increases to a d10 INSTEAD of the normal damage die (that presumably is still a d6). What is the reason for including the word "normal" in the damage rules, if not to make the calculation for damage on a pick with striking rune that crits (1d6+1d10+str)*2 + 1d10? Most of the examples I've seen on the net has this calculation at (2d10+str)*2+1d10, and that may well be correct, but why can we ignore the part about "normal" in the damage rules? A similar trait, the 2hand 1d12 trait, specifies that the d12 damage die when wielding it with 2 hands also applies to damage dice from a striking rune, while the fatal trait has no such text.

The actual striking rune rule does not include "normal" in the description of the damage dice added, increasing my confusion.

The calculation of (2d10+str)*2+1d10 is ubiquitous on the internet and I'm sure it's correct, but I'm trying to get a deeper understanding of the rules here and would appreciate you helping me out understanding WHY it's correct (why "normal" can be ignored in the damage rules).

[Ectar]

+1 striking pick w/ +4 str mod:

(2d10+4)*2 +1d10
2d10 (replacing the usual 2d6 from a pick, because fatal replaces the d6s with d10s.)
+4 str mod
*2 from critting
+1d10 fatal adds a dice, as well as replacing the original die size of d6

[Ruzza]

It looks like you're overcomplicating a straightforward process:

Striking Rune wrote:

A striking rune stores destructive magic in the weapon, increasing the weapon damage dice it deals to two instead of one.

Fatal Trait wrote:

The fatal trait includes a die size. On a critical hit, the weapon’s damage die increases to that die size instead of the normal die size, and the weapon adds one additional damage die of the listed size.

You're focusing on an undefined word such as "normal" that doesn't exist in the game, but does exist as an adjective that helps to separate weapon dice with the rune and weapon dice without the rune. You would be rolling the (2d10+STR Mod) x 2 + 1d10.

[Captain Morgan]

The one thing that trips me up about fatal and things that add damage bonuses per die is "extra dice" like Power Attack. But the basic fatal and deadly rules are really straightforward barring those examples.

[Perpdepog]

Wait, why are we adding the Fatal die outside of the crit multiplier? I always saw it as being included in the formula, so a +1 Striking Pick would look like,
(3d10 +4)*2, not
(2d10 +4)*2 +1d10

Deadly specifically says you don't multiply its additional dice, which is what makes me think that you are intended to multiply the additional die with Fatal, since it doesn't contain similar language.

[Finoan]

Perpdepog wrote:

Wait, why are we adding the Fatal die outside of the crit multiplier? I always saw it as being included in the formula, so a +1 Striking Pick would look like,

(3d10 +4)*2, not
(2d10 +4)*2 +1d10

Deadly specifically says you don't multiply its additional dice, which is what makes me think that you are intended to multiply the additional die with Fatal, since it doesn't contain similar language.

Examples given in the rules are not exhaustive by default.

Doubling and Halving Damage wrote:

Benefits you gain specifically from a critical hit, like the extra damage die from the fatal weapon trait, aren't doubled.

That would apply equally to Fatal as well as Deadly. Or any other damage that is only dealt on a critical hit but not on a regular hit - like the damage from Trip crit.

Edit: Honestly, that sentence should be its own paragraph - or at least part of the first paragraph. Not tacked onto the end of the paragraph about the GM being permissive about rolling first and doubling or rolling twice the number of dice.

[Perpdepog]

Ah, thanks. I've been running Fatal wrong this whole time then; I'll let my GM know.