How do crits work in PF?

[Thump]

What modifiers do you multiply along with the weapon's damage?

Example:

I am an Orc Barbarian with a STR of 20, wielding a falchion.

I get a crit, confirm it.

Do I just do the 4d4+7 because of 1.5x STR on two-handed weapons, or does the STR modifier get doubled as well?

[Blisstake]

All modifiers to damage, except for precision damage (such as sneak attack), and anything specifically mentioned (flaming weapon damage), are multiplied on a critical. So you would deal 4d4+14 damage on a critical.

[Thump]

Does that mean power attack damage is also multiplied?

In my campaign, I have a +1 keen elven curve blade, and I have 20 STR, so does that mean I would do 2d10+14 PLUS double the regular power attack damage?

[Armand]

Exactly...

edit: not 2d10+14 actually, +16, since your sword is +1, (which again double because of crit)

[Hylas]

The question was already answered but to help clarify if you have an elven curve blade, 18 STR, and Power Attack (level 1, for example), then on a normal hit you will do:

1d10 + 6(STR, 2 handed) + 3(PA, 2 handed) = 1d10+9

On a crit you will do 2d10+18.

If you're a rogue with a flaming curve blade then you will do 2d10+18+1d6(flaming)+1d6(sneak attack) because flaming and precision damage aren't multiplied on a critical hit.