# [RPG] How to roll for damage with a critical hit

critical-hitpathfinder-1e

From the Pathfinder Game Master’s Guide:

Critical Hit
Whenever a creature’s attack roll is a 20 on the d20, the attack might be a critical hit. Make another attack roll for the creature, just like the first one. If this second attack roll would hit the target, the original attack is a critical hit and does double damage—roll the damage for the weapon twice (including modifiers) and add the rolls together to find out how much damage you do. […]

To me this explanation sounds ambiguous, so please help me to understand this right. I'll give you an example fight. Let's assume a Goblin is fighting against Valeros the Fighter. Valeros hits first. The stats are as follows:

Goblin
Armor Class: 16

Valeros the Fighter
Weapon: Longsword
Attack Bonus: +4
Weapon Damage: 1d8+4

What I understand is how a critical hit may fail.

Failing Critical Hit
Valeros rolls a 20 on a d20, so his attack might be critical. He rolls again, but only a 11 on the d20. Even with his attack bonus of +4 his roll is lower than the Goblin's armor. The critical hit fails, but since the first roll was highter than the Goblin's armor, Valeros will deal 1d8+4 damage.

How much damage does Valeros do on a critical hit?

Valeros rolls a 20 on a d20, so his attack might be critical. He rolls again, this time 15 on the d20. With his attack bonus of +4 his roll is higher than the Goblin's armor.

The manual says that "the original attack is a critical hit and does double damage". At this point I haven't rolled for any damage. I would assume that the damage roll I do next will double. So 1d8+4 times two could be 2x(8+4)=24.

In the same sentence I read that I have to "roll the damage for the weapon twice". So I could also roll (8+4)(1+4)=17.

So what is true? How do I roll for damage?

The thing I think you're missing here is that the description of "double damage" is all one sentence.

[...the attack] is a critical hit and does double damage—roll the damage for the weapon twice (including modifiers) and add the rolls together to find out how much damage you do.

Let's break it down.

the attack is a critical hit

Cool, now we've determined what it is, what does that mean?

and does double damage

That's a bit ambiguous. There's more than one way to think about "double damage" (as your post demonstrates.) But here comes the clarification:

roll the damage for the weapon twice (including modifiers) and add the rolls together to find out how much damage you do.

That's not a separate thing, that's the explanation of what they mean by "double damage" immediately before it. In your example, you'd roll (1d8+4)+(1d8+4), which might well be 1+4+8+4=17. Really, you're still doubling the damage you do, just before you roll instead of after.