Pathfinder 1E A question about spellcasting and injury

Preface: I've been playing D&D since it was three saddle-stitched books. I haven't done much with Pathfinder. I normally hang on the
Older Editions D&D" forum, not here.

I dropped by my FLGS today and saw some friends playing a Pathfinder game. I wasn't in it but I listened for a bit and I heard people talking about how important it was for a caster to be high in the initiative order. The way they were playing it, if a caster took any damage in the round prior to their action, they had to make a Concentration check or the spell fizzled.

The D20 system introduced the "cyclic initiative" concept, that there wasn't a true "start" and "end" to the round as such, but that spells and other effects would run from a character's action in one round until their action in the next. In other words, other than in the first round, Initiative dictated the sequence in which characters acted, but that there wasn't any significance to that moment after Initiative of 1 and the top of he order. So there was no "before" or "after" as such. After one was before the next, regardless of which initiative count it came on. No miraculous "reset" of anything after Initiative 1.

In D&D the rules for Concentration checks being called for due to damage said that they came up when the character took damage while casting. The idea of having a spell fail because of damage taken in the round was a leftover from 1st edition.

I checked the Pathfinder rules and they said the same thing.

The DM explained that this had been corrected in the FAQ. I looked and couldn't find any such thing.

So can one of the Pathfinder gurus here clarify this? Is there any kind of official FAQ for Pathfinder that says damage taken prior to casting (not "while" casting), and in the same round, forced the caster to make a Concentration check or lose the spell?

If so, can someone post a link? It seems really strange that a later edition of the D&D-ish family should throw back to 1st edition.

I have to admit, this is a new one on me.

Thanks for the Exp, Hrothgar Rannúlfr. This is the first time I've been commended for a question nobody seems to want to answer.

To simplify the question: The rules for casting a spell say that a Concentration check is called for if the caster takes damage *WHILE CASTING*. One DM says that there's a FAQ that clarified this to mean "Takes damage before or during their initiative".

I'm trying to verify that this is in the errata or a FAQ for Pathfinder. I haven't seen anything like this since 1st/2nd edition D&D.

The PRD is pretty up to date:
http://paizo.com/pathfinderRPG/prd/coreRulebook/magic.html#table-9-1-concentration-check-dcs

...I am not aware of any concentration checks needed for damage taken prior to casting unless it is 'continous' damage. In other words, it comes from a spell or environmental source and not from something like a previous melee wound (unless it has a bleed effect). I also play bi-weekly in Pathfinder Society with folks who are pretty much rule fanatics and we do not play as you mentioned above.

...Unless you're casting a spell that takes a full-round to cast, and not a standard action, you shouldn't have to make a concentration check if you take damage prior to the casting. Continuous damage usually takes place at the beginning of a character's turn.

"Injury: If you take damage while trying to cast a spell, you must make a concentration check with a DC equal to 10 + the damage taken + the level of the spell you're casting. If you fail the check, you lose the spell without effect. The interrupting event strikes during spellcasting if it comes between the time you started and the time you complete a spell (for a spell with a casting time of 1 full round or more) or if it comes in response to your casting the spell (such as an attack of opportunity provoked by the spell or a contingent attack, such as a readied action).

If you are taking continuous damage, such as from an acid arrow or by standing in a lake of lava, half the damage is considered to take place while you are casting a spell. You must make a concentration check with a DC equal to 10 + 1/2 the damage that the continuous source last dealt + the level of the spell you're casting. If the last damage dealt was the last damage that the effect could deal, then the damage is over and does not distract you."