Explosive Bomb
Benefit: The alchemist’s bombs now have a splash radius of 10 feet rather than 5 feet (see Throw Splash Weapon). Creatures that take a direct hit from an explosive bomb catch fire, taking 1d6 points of fire damage each round until the fire is extinguished. Extinguishing the flames is a full-round action that requires a Reflex save. Rolling on the ground provides the target with a +2 to the save. Dousing the target with at least 2 gallons of water automatically extinguishes the flames.
Does your target take the addition 1d6 fire damage from being on fire on the same round that it is hit with the bomb or on each round after it is hit before the fire is extinguished?
If so, does it get the save on that initial round?
Yes, they start on fire immediately.
During their first turn after being taught that they are flammable, they can make the saving throw.
I was under the impression that 'Catch on Fire' damage was dealt on your turn since it was your action that caught them on fire. On their turn they can perform actions to put themselves out, but if they fail they are still on fire when your turn comes around.
The Core Rulebook, on page 444, talks about a generic catching on fire where it has its own Reflex save and damage, but I don't think this applies to spells and bombs since they already have a saving throw and the damage doesn't occur immediately. Other than that, it says "In each subsequent round, the burning character..." which I take as the same round as the bomb/spell attack not the NPC's.