Double Damage?

Hi all

A simple question:

According to the core rules, a double damage on a critical hit means rolling damage twice and adding those up as opposed to actually doubling on one damage roll.

I am looking into different critical roll apps and I see that many of them have "double damage" as an effect, including the Paizo official decks.

Would you say that double damage in this case is exactly the same as the double damage in core rulebook, or is it actual double damage? Could be the Paizo ones follow the core rulebook but others not necessarilly? I'm a bit confused regarding the interpertation of Double Damage as a special effect.

Thanks.

Double damage always means rolling the weapon dice twice. I don't believe there are any circumstances where you literally multiply damage.

It always means rolling damage dice more times.

Double - Roll 2 times add bonuses 2 times.
Double Double - Roll 3 times add bonuses 3 times.
Double Double Double - Roll 4 times add bonuses 4 times.

etc., etc.

Great, thanks so much!