The Drunken Lizard Pub

Ive always wondered about how alchemy works with elemental damage. Does anyone know what you get when imbuing a weapon with say poison, cold or fire damage? Do you get a chance to do 1-5 elemental damage or do they have to save against it.

You always do the damage, but monsters have a save throw (unless they are immune where I guess there is no need for a throw).

If a monster succeeds his throw, you only do the weapon normal damage, without the enchantment (but you still do damage).