Adjusting CR due to environmentals, and undefined properties in PF

[Basara549]

I'm currently running a World's Largest Dungeon campaign in Pathfinder, making the necessary adaptations along the way from D20.

I've ran into a few issues (considering the bugs in the module, it's not unexpected - they even managed to even put an item from 2E that didn't make it into 3E into the module):

1. There's a lot of armor showing up with "Unholy" as a property. What should I convert it to?
Dastard? Does damage if touched like an unholy weapon? OR, something else?

Now, the hard part. Are there any guidelines for adjusting the effective CR for an encounter due to environmental conditions and other modifiers?

Here's the issue where this came up.

Party is 4 level 5s (2 5s, a 1/4 and a 2/3) of melee types, and a level 7 cleric.

Foes are CR 3; 6 Ghouls with 2 levels of Antipaladin, created by a curse, so they aren't standard ghouls per se, but aren't quite ghasts either.

But, they have the following innate:
All normal Ghoul properties (including turn/channel resistance), PLUS can effect Elves as ghasts would.
Spell Resistance 14
Feats: Multiattack (so they can 5-foot and use sword/claw/bite routine), Weapon Focus (LS)
Each has an Unholy Longsword +1 (plus the undefined "unholy" chainmail +1), meaning that the typical hit on a good party member will take them down 30-50% of their hit points.
Additional natural armor bonuses to raise their AC to 23, and flat-footed AC to 20.
Skills and stats give them a stealth +9.
While still 4 HD, the original creatures were written up as 4D12 HP.

In addition, the ROOM they are in has the following modifiers
* Area inflicts a -5 penalty to all PC Will saves
* Area has a base DC 14 Fear check when entered, or be Shaken for 1D4+1 rounds - that effectively becomes DC 19, with the will save penalty above.
* Two separate, cumulative, modifiers that give them an additional +10 channel resistance, and a 3rd that prevents use of Turning. Even the 7th level cleric with a +2 Feat bonus to Channel DC only does full damage from a channel if the creature rolls a 3 or less on its save.
* Additional bonuses to Stealth that give the monsters effectively +17 to stealth even with their armor penalties
* Terrain prevents characters (but not the monsters) from using 5-foot step, and requiring a DC 16 dex check to move more than half movement.
* Characters are at -10 to Perception checks
* Characters treat all ranged attacks as if target is Concealed
* Characters take 1 point of negative energy damage every 10 rounds

After the party BARELY survived this encounter, I'm now at a loss to determine the XP value of the encounter, because of all the buffs the module writer gave them - CR 3 is definitely too low.

In my days as a 1E & 2E AD&D DM, I could have used the tables from those books to modify the XP values, but for the later incarnations of D&D and PF, I haven't been able to find any equivalent.

So, what would you suggest I raise the CR to - or what kind of blanket XP bonus would you suggest?

[Mystic Lemur]

Why not just use Unholy?

As for the other question, the CR system is a rough abstract at best.

-Do you think they had a bad time because the monsters were innately too tough? If so, adjust the CR by 1-2 as you feel appropriate.
-Do you feel they had a rough time because they fought too many at once? 6 CR3 monsters is somewhere around Encounter Level 7-8. If the group is only level 3-5, then it's no wonder the fight was challenging, and the XP is correct.
-Do you feel the encounter was tough because the PCs handled it poorly or just weren't prepared? Then the XP is appropriate. Don't reward them more for bad decisions, or they will keep making them.

The 3.x DMG had a rough conversion. If the environment heavily favored the monsters, consider awarding 125-150% XP, if the environment heavily favored the PCs consider awarding 50-75% XP.

[Basara549]

Well, the module (World's largest Dungeon) is chock full of "Unholy" as an ARMOR property. All of the undead were wearing it, and there's a lot more of it as loot in section C. As an Armor property, it would be pretty much useless unless accidentally donned by a good person, unless you had a Good monk punching/kicking/grappling the armor, and ruled they were taking the 2D6 from touching it on successful attacks. I'd rather have it as something more than simply a "you can't wear that" window dressing property. By some chance was Unholy a 3.0 property that got made into weapon only in 3.5?

In all, the real problem is dealing with the source material - after all, that adventure actually has a full page encouraging the GM to _cheat_ (and listed almost 20 ways) to make life harder on the PCs. It was also poorly edited (room numbers and descriptions off, a 1E/2E only item in a 3E module, etc.). I'm almost having to put as much energy into converting it as I would to have just taken the maps and fleshed it out with new stuff from scratch.

The original encounter was for 4 CR3, but I'd raised it to 6 monsters because of their track record. What I didn't take into account was the synergy of ALL the environmental conditions/bonuses/penalties listed, until we were into it.

The party in the past has treated 4 CR3s as a cakewalk (in fact, 4 of them had killed a random encounter with 4 dire wolves in 5 rounds an hour earlier, before the 5th level fighter even showed up), from their rather adept skills at min-maxing (one player even has a barbarian1/monk4, from my co-GM allowing him to take the Urban Barbarian & Martial Artist archtypes to bypass the alignment restrictions). And to beat it all, the closest thing to an arcane spellcaster in the lot would either be a 3rd level bard, or the cleric's Fire domain spells (that he never even got a chance to use from line of sight and the fact that the monsters focused on the cleric once they saw there was a cleric (the cleric was stuck doing channels for healing most of the fight, and never had LOS to channel for damage against more than two at a time - one of which was in the cleric's face doing full attacks.
HALF the party even took down an EL 10 once (and when no one was above level 5), by a combination of luck, skill, and ignorance (their attack should have ended in defeat, and I was fully prepared to have to replace half the party the next game session - but they got really lucky).

[Eltacolibre]

Conversion are actually a lot more complicated than they are suggested in the gamemastery guide for pathfinder. But anyway I tend to agree that anything from 3.5 is usually at least CR-1. While I wouldn't encourage you to pathfinder everything, way too much work, I wouldn't worry about the environment ad hoc cr adjustment.