Drow of the Underdark Errata

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I've now finished the Lizards.


pg. 134 - Footpad Lizard -
The creature is large (long), but has reach as if it were large (tall).

pg. 134 - Quicksilver Lizard -
The creature is large (tall), but has reach as if it were large (long).

pg. 135 - Subterranean Lizard -
The creature has 2 hp too few.
The creature is large (long), but has reach as if it were large (tall).
The creature's bite attack receives double the Strength bonus in extra damage (as if it were the only natural attack), despite having a tongue attack as well.
The creature's Climb skill modifier of +12 should be listed.
pg. 84 - Claws of Influence - This class feature should probably indicate that it is a mind-affecting ability.

pg. 84 - Swift Enchantment - This class feature allows you to take an immediate action to cast a spell as a swift action, but taking an immediate action takes the place of your swift action for the next round. The class feature should probably state that you can release somebody from the effects of your claws of influence class feature as a free action in order to cast an enchantment as a swift action. The class feature should also probably note that the enchantment spell must be cast before the end of your round.

pg. 84 - Irresistible Charm - There are several things wrong with this class feature. The first is that it provides no duration during which the effect must be used; a character could release a subject from their claws of influence upon awakening in the morning and use the benefit hours later. The second problem is that it requires a swift action to release a subject when it should probably only require a free action. The final problem is that the benefit is horrifyingly unbalanced. Being able to boost save DC's by your Charisma modifier when Charisma is likely to be your primary spellcasting attribute is absurd. A Sorcerer PC with an ECL of 17 could have an effective Charisma score of 35 (18 base + 2 racial bonus + 4 ability boosts + 5 inherent + 6 enhancement). Add Spell Focus (enchantment) and Greater Spell Focus (enchantment) and the character will be able to cast 6th level enchantment (charm) spells with a DC of 42.

pg. 85 - Irresistible Compulsion - There are several things wrong with this class feature. The first is that it provides no duration during which the effect must be used; a character could release a subject from their claws of influence upon awakening in the morning and use the benefit hours later. The second problem is that it requires a swift action to release a subject when it should probably only require a free action. The final problem is that the benefit is horrifyingly unbalanced. Being able to boost save DC's by your Charisma modifier when Charisma is likely to be your primary spellcasting attribute is absurd. A Sorcerer PC with an ECL of 20 could have an effective Charisma score of 35 (18 base + 2 racial bonus + 4 ability boosts + 5 inherent + 6 enhancement). Add Spell Focus (enchantment) and Greater Spell Focus (enchantment) and the character will be able to cast 7th level enchantment (compulsion) spells with a DC of 43.

You forget that the PrC sucks BALLS. No one in his right mind would even consider giving up 5 caster levels. Your theoretical ECL 20 character would not be able to cast 7th level spells, as his effective sorcerer caster level is 13. (He lost 5 from the PrC and 2 from drow level adjustment). A wizard, on the other hand, would be able to cast such spells-but definitely not at DC 43.
You forget that the PrC sucks BALLS. No one in his right mind would even consider giving up 5 caster levels. Your theoretical ECL 20 character would not be able to cast 7th level spells, as his effective sorcerer caster level is 13. (He lost 5 from the PrC and 2 from drow level adjustment). A wizard, on the other hand, would be able to cast such spells-but definitely not at DC 43.

True. I accidentally counted spell progression as a Wizard instead of a Sorcerer. The Drow in question would need to be level 21 before gaining the DC 43 7th level spell. That doesn't change the fact that the character is casting spells with an absurd DC. If I had a character who took 3 levels as a specialist Wizard, two levels as a Master Specialist, and then two levels each of 8 different prestige classes with strong Will saves, and then gave this 21st level character a Cloak of Resistance +5, the Iron Will feat, and an effective Wisdom score of 18, then he'd still have a chance at failing his saving throw against the hypothetical Insidious Corruptor, since he'd only have an effective Will save bonus of +41. The vast majority of characters would be incapable of making such a saving throw with anything less than a natural 20. For the chance at casting mind control spells that nobody short of a god or a Will save munchkin will be able to save against with anything less than a natural 20, I'd be willing to forego 5 caster levels. After all, who needs high level spells when your Charm Person has a DC of 37.
I've just finished the Quaggoths. The base creature was okay, but the advanced versions had some problems.


pg. 136 - Greater Quaggoth - In order to get the ability scores listed in this section to more fully match the example character on page 138, switch the Strength and Wisdom entries so that the Strength is 13 and the Wisdom is 12.

pg. 136 - Quaggoth War Leader - In order to get the ability scores listed in this section to more fully match the example character on page 138, switch the Strength and Wisdom entries so that the Strength is 13 and the Wisdom is 12.

pg. 138 - Greater Quaggoth -
The creature's trap sense bonus should be noted on its AC line.
The creature has, while raging, 3 hp too many.
The creature's trap sense bonus should be listed on its saving throw line.
The creature's SQ entry should include illiteracy.
Reduce the creature's Wisdom from 15 to 14. This will not change anything involving the Wisdom score, but will correct a problem with the Strength score.
The creature has, while non-raging, 3 hp too many.
The creature's non-raging Skill block should list his Knowledge (nature) modifier of +2 because of his Survival synergy, and should also note that the creature can only make DC 10 Knowledge (nature) checks.
The creature has 4 skill points too many.

pg. 138 - Quaggoth War Leader -
The creature's trap sense bonus should be noted on its AC line.
The creature should have 11 HD instead of 10.
The creature has, while raging, 6 hp too few.
The creature's trap sense bonus should be listed on its saving throw line.
The creature's SQ entry should include illiteracy.
Reduce the creature's Wisdom from 15 to 14. This will not change anything involving the Wisdom score, but will correct a problem with the Constitution score.
The creature should have 11 non-raging HD instead of 10.
The creature has, while non-raging, 4 hp too few.
The creature's non-raging Skill block should list his Knowledge (nature) modifier of +2 because of his Survival synergy, and should also note that the creature can only make DC 10 Knowledge (nature) checks.
The creature has 2 skill points too many.
I've finished the Shunned and the Spiders. None have any outright errors, but two have things that should be probably be changed.


pg. 141 - Shunned -
There should be some sort of limit to how many spider swarms a Shunned can have active at a time and possibly on how long the swarms can remain active. Without these limits, a Shunned can create an average of 240 spider swarms every hour. If you assume that it spends 16 hours spitting out spider swarms, then that is an average of 3,840 spider swarms per day (every one under the complete control of a chaotic evil being that seeks to bring suffering to all creatures).

pg. 142 - Tangle Terror -
The creature's Maddening Webs attack should probably require a Fortitude save instead of a Will save and should likely note that creatures immune to poison are immune to the effect.
I've finished the monster chapter. Now I'll go on to the chapter full of dozens of drow NPC's.


pg. 146 - Filth-Eater -
The creature has darkvision 90 ft. While the Troll entry in the Monster Manual agrees with this, the Trolls as Characters entry in the same book lists the range as 60 feet.
The creature's trap sense bonus should be noted on its AC line.
The creature has 7 raging hp too few.
The creature's trap sense bonus should be listed on its saving throw line.
The creature is missing an ability score increase. Any score other than Intelligence can be raised by 1 without changing anything else. Raising Intelligence grants 1, 5, or 6 extra skill points (depending upon which level was used for the increase).
The creature's SQ entry should include illiteracy.
The creature has 7 non-raging hp too few.
The creature's non-raging grapple bonus should be +23 instead of +21.
The creature seems to have an immunity to normal disease, a +4 racial bonus to Fortitude saving throws, and a disease attack (which strangely becomes more virulent when it gets angry), yet receives no increase to CR from these abilities.

pg. 146 - Tunnel Thug -
I think that the creature's CR is 1 higher than it should be (unless the use of the elite array of ability scores has increased the CR by 1, in which case the Filth-Eater's CR should be increased as well).
Studded leather armor allows a maximum Dexterity bonus to AC of +5. Reduce the creature's AC, touch AC, and flat-footed AC by 2.
The creature's trap sense bonus should be noted on its AC line.
The creature has 2 hp too many.
The creature's Will save is 1 point too low (+2 race, +1 Rogue, +1 Assassin, +1 Wisdom, +2 feat = +7).
The creature's trap sense bonus should be listed on its saving throw line.
The creature is missing an ability score increase. Raising Intelligence by 1 will allow it to cast 2 Assassin spells each day.
The creature's Knowledge (nature) modifier should note that the creature can only make DC 10 Knowledge (nature) checks because the entire modifier is from its Survival skill synergy.
The creature's skill block should note Speak Language (Undercommon).
The creature lacks sufficient ranks in Hide and Move Silently to enter the Assassin prestige class. As the creature is also 3 skill points too short, Add 4 ranks to Hide and 3 ranks to Move Silently while subtracting 4 ranks from Climb.

pg. 148 - Venom Ooze -
Why does a blind cerature have a Spot modifier?
The creature's Corrupt Water ability requires it to remain submerged for at least an hour. Since the creature is not listed as being aquatic (amphibeous), wouldn't it drown well before an hour of submersion?
The creature's +8 racial bonus to Swim checks technically only applies to special actions and avoiding hazards. The entry should probably change from Swim +16 to Swim +8 (+16 involving special actions and avoiding hazards).
I'm back with some more errata. I've been very busy at a temp job with a very long commute. I may be very slow with my updates for awhile.


pg, 160 - Anybys Velifane -
The NPC does not meet a prerequisite for her Archmage prestige class. Since she is missing a feat, give her Spell Focus in any school other than evocation, illusion, or necromancy and adjust her spell DCs appropriately.
The NPC should know three bonus languages rather than one.
The NPC's deflection bonus to AC should be +2 instead of +4 (+2 ring of protection).
The NPC's armor bonus to AC should be +8 instead of +6 (greater mage armor spell + force armor SQ).
The NPC has 1 hp too few.
The NPC's melee weapon should possibly have a seperate entry for when the elf bane property is applied (in the same manner as the entry for the Quaggoth War Leader).
Empower Spell should not be listed as an attack option.
The NPC's CL should be 19 instead of 20 (10 Evoker + 4 Argent Savant + 4 Archmage +1 spell power SQ).
The NPC's roll to overcome SR should be 1d20+21 instead of 1d20+22.
The NPC has one 9th-level spell slot too many (she has 9th-level spell slots as is she were a 19th level Wizard, but she is only effectively an 18th level Wizard because her first level of Argent Savant does not increase spellcasting).
The NPC has one 7th-level spell slot too many (she looses one slot to gain her mastery of counterspelling class feature).
The NPC has one 6th-level spell slot too many (she looses one slot to gain her mastery of shaping class feature).
The 5th-level stilled orb of force spell should include a ranged touch bonus of +14 (12 + force specialization class feature).
The NPC has one 4th-level spell slot too many (she looses one slot to apply her spell-like ability class feature to the force missles spell).
The 2nd-level blast of force spell should include a ranged touch bonus of +14 (12 + force specialization class feature).
I am unsure if the NPC's spell power class feature applies to the CL of her spell-like abilites. If not, then lower their CL by one.
The NPC's ability scores are higher than the elite array. Reduce either her Strength score (decreasing dagger attack/damage and grapple checks by 1) or her Charisma score (reducing Bluff, Diplomacy, and Use Magic Device skill checks by 1) from 10 to 8.
The high arcana SQ should be replaced by spell power.
The NPC's SQ should indicate her ability to sense hidden doors when passing within 5 feet.
Eschew Materials and Spell Penetration do not qualify as Wizard bonus feats. Remove the bonus annotation from both and add bonus annotations to the Empower Spell and Still Spell feats.
The NPC's Spellcraft skill modifier should note her situational bonus to learning evocation spells.
The NPC's skills entry should list Survival due to the +2 tracking synergy that she receives from Search.
The NPC has no actual ranks in Use Magic Device. Since the skill can only be used trained, delete the entry despite the bonus from the Magical Aptitude feat.
The NPC's skill block seems to assume that she has had a 20 Intelligence score since 1st level and that she took her ranks in Search cross-class (rather than as Archmage class skills). Assuming a starting Intelligence of 17 (15 from elite array +2 racial), ability increases at 4th, 8th, and 12th HD, and that Search was taken as a class skill, then the NPC has 14 skill points too many.


As an aside, how the $@!% is anybody supposed to make sense of this stat block without opening up a half dozen books for explanations as to how things work? To make full use of this NPC, I'd need to open this book, the Book of Vile Darkness, Complete Arcane, Dungeon Master's Guide, Planar Handbook, and Spell Compendium. WotC sources assured the public that the new, easier to use stat blocks would provide the information needed to run an encounter without flipping through a bunch of books, but the only character trait that gets an actual explanation is Light Blindness. What do the esoteric class features of the Argent Savant and Archmage actually do? WotC apparently feels no need to inform the reader.
pg. 161 - Keveras Lorakythe -
The NPC's initiative modifier should be +4 instead of +6. I assume that an early version of the ring of anticipation gave a +2 bonus to initiative rather than letting you roll initiative twice.
The NPC's trap sense bonus should be listed as an AC modifier.
The NPC was only given average hp at first level. Increase hp to 44.
The NPC's trap sense bonus should be listed as a saving throw modifier.
The NPC's melee damage bonus is wrong. The NPC should get 1.5 times his Strength modifier added to damage for using a two handed weapon (3 damage) and inflicts additional damage, equal to his Intelligence modifier (2 damage), to foes susceptible to critical hits.
The NPC's SQ should indicate his ability to sense hidden doors when passing within 5 feet.
The NPC should not have a Slight of Hand modifier listed as he has no ranks in the skill, and Sleight of Hand cannot be used untrained.
The NPC's Listen and Spot modifiers should actually be 10.5 instead of 11. Lower one to 10 and keep the other at 11 (or lower both to 10 and keep Slight of Hand while raising its modifier to +8).
As an aside, how the $@!% is anybody supposed to make sense of this stat block without opening up a half dozen books for explanations as to how things work?

Check out the latest Dragon article. Same deal.
pg. 162 - Lady Thandysha -
The NPC has 17 hp too few (the writer forgot her Constitution bonus and rounded up instead of down).
The NPC should be noted as possessing resistance to fire 5 because of her greater piwafwi.
The NPC's Reflex save entry should be +8 instead of +10.
The NPC's saving throw line should list her True Believer feat as a potential modifier.
The NPC's main melee attack includes the drowcraft bonus into the attack roll but not into the damage roll. Increase the damage bonus to +4.
The wall of evil and wrack spells are [Evil] and should therefore be CL 19.
The spell-like ability granted by the queen's scourge should be CL 12.
The NPC seems to be based on a 29 point ability buy rather than a 25 point ability buy.
The NPC's SQ should indicate her ability to sense hidden doors when passing within 5 feet.
The NPC should not have a Slight of Hand modifier listed as she has no ranks in the skill, and Sleight of Hand cannot be used untrained.
The NPC should not have a Use Magic Device modifier listed as she has no ranks in the skill, and Use Magic Device cannot be used untrained.
The NPC is short 9 skill points.
The NPC's possessions entry notes that information on both the greater piwafwi and the drow house insignia can be found in the Lords of Darkness supplement. Why give these references when the drow house insignia is covered on page 99 of this book while a notation on page 97 indicates that the greater piwafwi can be found in the Magic Item Compendium?

Despite the errors, I have to say that I am impressed that, for once, they gave a Cleric an aligned aura as a SQ. I've pretty much stopped bothering to note such things as errata since I never see it done correctly.
pg. 163 - Mindshard -
The NPC's touch AC should be the same as his normal AC (touch AC only ignores armor, shields, and natural armor).
The NPC is 3 hp short (he was given average hp at first level).
The NPC's Will save should be +7 (+9) instead of +8 (+10).
The NPC's Quick Recovery feat should be listed either with his saving throw entry or with his resist entry.
The NPC should take a -4 penalty to saves versus mind-affecting abilities thanks to his rending claw graft.
The NPC's rending claw melee attack is a natural attack and thus should not receive an iterative attack progression.
I am unsure if Combat Casting actually counts as an attack option.
The NPC's hellrime blast should have a DC of 19.
The NPC's ability score array only adds up to the equivalent of a 25 point elite array if you assume that a base Intelligence score of 7 gives back 2 points.
The NPC's SQ should indicate his ability to sense hidden doors when passing within 5 feet.
The NPC's Concentration modifier should change from +6 to +6 (+10 to cast defensively or while grappled/pinned).
The NPC's skills entry should indicate that he spent 2 points to learn Drow Sign Language. Remove two ranks from Bluff and add Speak Language (Drow Sign Language).
pg. 164 - Xil'etha Dhuvaryl -
The NPC should have the psionic subtype because she has levels in a psionic class.
The NPC has Kuo-Toan as a starting language despite the fact that it is not listed as a bonus language on page 36. Since it was listed as a bonus language in the Monster Manual you can either assume that it was accidentally left off of page 36 or that it was purposefully removed but that the example NPC did not take the change into account.
The NPC has 3 hp too many.
The NPC's speed entry should probably note her Psionic Charge feat.
The NPC's attack entries do not account for the burst aspect of the psychokinetic burst weapon.
The NPC's ranged attack option should note that she can throw a mind blade in the shape of a longsword or a bastard sword.
The stat block should note somewhere that the NPC's Wild Talent feat grants her 2 power points.
The NPC is 1 attribute point short of being a 25 point character. Increase her Constitution score to 14, raise her hp to 79, increase her Fort save to +5, and raise her Concentration modifier to +6.
The NPC's SQ should indicate her ability to sense hidden doors when passing within 5 feet.
The NPC's Jump modifier should note that her modifier increases to +16 while her Speed of Thought feat is active.
pg. 165 - Drow Assassin -
The NPC is short 3 hp.
The NPC's ranged weapon should possibly have a seperate entry for when the human bane property is applied (in the same manner as the entry for the Quaggoth War Leader).
The NPC cannot cast 3rd level assassin spells because his/her Intelligence score is only 12.
Even if the NPC could cast 3rd level spells, the bonus on the melee touch attack would be +14 instead of +13.
The NPC's ability scores only adds up to an elite array if you lower his/her Strength, Dexterity, or Constitution score by one point (while making appropriate adjustments elsewere to accomodate the change).
The NPC's SQ should indicate his/her ability to sense hidden doors when passing within 5 feet.
The NPC should have poison use as an SQ.
pg. 166 - Drow Inquisitor -
The NPC meets none of the feat requirements to enter the Blackguard prestige class.
Why does the NPC have an evil aura listed (presumably from her Cleric and Blackguard levels) on the aura line when the character on page 162 had her Clerical aura of evil listed on her SQ line?
The NPC's light fortification should be listed on her hp line.
The NPC has 3 hp too few if her first level was Rogue, 4 hp too few if her first level was Cleric, and 5 hp too few if her first level was Fighter. Assume that Rogue was her first level for the extra skill points.
I am unsure where the NPC gained a 1/day blur effect.
The NPC's melee entry notes that her weapon functions as a +1 good outsider bane morningstar. The Entry for the weapon on page 102 indicates that it functions as a +1 morningstar. Either modify the item entry or modify the stat block. Furthermore, if the weapon is indeed supposed to be a good ousider bane weapon, then simply adding 2d6 damage against good outsiders is insufficient, the weapon would also gain a +2 to attack and damage rolls against good outsiders.
The NPC's melee entry seems to assume that she will wield her weapon in two hands (despite needing to keep a hand free for spellcasting).
Delete the second melee entry. It appears to be a failed attempt at applying the good outsider bane property to the weapon.
I believe that the NPC's special actions entry should indicate spontaneouus casting (inflict spells).
I believe that the NPC's Evil domain increases the CL of all Evil spells (not just Cleric spells) that she casts. If that is so, then increase to 7 the CL of the spells summon monster III, demonhide, and summon monster I.
I believe that, unless a character has the Weapon Finesse feat, they resolve melee touch attacks using their Strength modifier. If that is so, then change the attack roll for the inflict light wounds spell from +16 to +14.
Although the NPC's ability scores add up to a 25 point character, they would still add up to a 25 point character if you raised her Strength to 15. This would affect nothing but her carrying capacity.
The NPC's SQ should indicate her ability to sense hidden doors when passing within 5 feet.
The NPC should have poison use as an SQ.
The NPC cannot have both the Sickening Strike and the Terrifying Strike feats, as she would not have qualified for either until 12th level and is currently 14th level.
Replace the feats Sadistic Reward, Sickening Strike, and Terrifying Strike (and remove reference to them in the attack options entry) with Cleave, Improved Sunder, and Power Attack, so that the NPC meets the Blackguard prerequisites.
The NPC is either short 4 skill points, assuming that her first level was either Cleric or Fighter, or 21 skill points, assuming that her first level was Rogue. Since it is more beneficial to assume that her first level was Rogue, give her 1 additional rank in Jump (+8 modifier), and 5 ranks in Balance (+10 modifier), Gather Information (+12 modifier), Knowledge (local) (+6 modifier), and Tumble (+10 modifier).
The NPC's Fiendish Servant should have an (augmented animal, extraplanar) notation.
The NPC's Fiendish Servant should have a natural armor bonus of +4.
The NPC's Fiendish Servant should have an AC of 18.
The NPC's Fiendish Servant should have a flat-footed AC of 15.
The NPC's Fiendish Servant has 1 hp too many (the writer rounded up).
The NPC's Fiendish Servant should have DR 5/magic.
The NPC's Fiendish Servant should have SR 10.
The NPC's Fiendish Servant should have magic strike listed as an attack option.
Should the NPC's Fiendish Servant receive an ability score increase for its 4th HD?
The NPC's Fiendish Servant should have a Climb skill modifier listed (+11) since it has a Climb speed and a resultant racial bonus to Climb checks.
pg. 167 - Drow Priestess -
The NPC has 1 hp too many (the writer rounded up).
The NPC's melee touch attacks for her spells should be made at +7 instead of +8.
The NPC's inflict light wounds spell should provide a saving throw DC (DC 15).
The NPC should have an SQ entry to indicate her ability to sense hidden doors when passing within 5 feet.
Given that two previous NPC's have had entries noting their evil auras (although each noted the aura in a different place), this NPC should also have an evil aura noted.
The NPC cannot have the Augment Summoning feat because she does not have the Spell Focus (conjuration) feat. Replace either Combat Casting or Spell Penetration with Spell Focus (conjuration).
If you haven't removed the NPC's Combat Casting feat, then modify her Concentration entry to +12 (+16 to cast defensively or while grappled/pinned).
Dude, if I ever find myself in need of a proofreader I'll be dropping you a note.

John Ling

Lead Pathfinder Developer for Frog God Games

pg. 168 - Drow Slaver -
The NPC's Initiative bonus should be +6 (+5 Dex +1 battle fortitude class feature).
The NPC's flat-footed AC should be the same as his normal AC because of uncanny dodge.
The NPC's Chosen Foe feat should be listed on the AC line next to skirmish and uncanny dodge.
The NPC has 4 hp too few.
The NPC's tenacious persuit class feature should be +20 ft.
The NPC's crippling strike attack option does not require a sneak attack.
The NPC should have an SQ entry to indicate his ability to sense hidden doors when passing within 5 feet.
The Chosen Foe feat should indicate that it is from this book.
The benefits of the Endurance feat should be listed on the NPC's saving throw and ability score lines.
The NPC's skill block should note his Knowledge (nature) modifier of +3 (+1 Int +2 synergy) and that he can only use the skill to make DC 10 checks.
The NPC's skill block should note the situational modifiers to certain skills from his favored enemy class feature.
The NPC's Jump modifier does not include his speed bonus to Jump checks. Increase the Jump modifier to +14.
The NPC's skill block assumes that his first level was Ranger. Since the only difference between taking Ranger and Scout at first level is 6 skill points, you can choose to add 6 skill points to Scout skills (splitting them between Hide and Move Silently may be a good idea).

pg. 169 - Drow Warrior-
The NPC should have an SQ entry to indicate his ability to sense hidden doors when passing within 5 feet.
The NPC is short 4 skill points. Add the points to either Climb or Jump (for a total modifier of +2 after accounting for the Strength bonus and AC penalty to the skill).
Sorry for the two week delay. There was a family crisis.

pg. 169 - Favored Consort -
The NPC's dodge bonus to AC should not be part of his normal bonuses to AC. The dodge bonus granted by the Dodge feat only applies to one opponent while the Shadowborn Warrior feat only grants a dodge bonus under certain conditions. Lower the NPC's AC, touch AC, and flat-footed AC by 1 point.
The NPC is 2 hp short. The writer gave him average hp for first level.
The NPC's saving throw entries imply that the cloak of the consort only penalizes his Will saves. The wording of the cloak's entry implies that it affects to all three saves.
The NPC should not have light blindness indicated as a weakness as it is negated by his cloak of the consort.
The spider boon quality applies to armor rather than weapons and thus cannot apply to the NPC's hand crossbow.
The NPC cannot have the enervation spell prepared because it is from one of his prohibited schools.
The NPC should be able to use his darkness spell-like ability twice each day due to his Instinctive Darkness feat.
The NPC should have an SQ entry to indicate his ability to sense hidden doors when passing within 5 feet.
The NPC is short one bonus feat (likely from his Eldritch Knight prestige class).
The NPC's skills block only adds up if you ignore the fact that Bluff, Diplomacy, Listen, and Spot are cross-class skills for all of the NPC's levels. Remove a total of 12 ranks from among the NPC's skills (note that Search is already being used at default).
The NPC does not need cloudkill listed in his spellbook as it is already listed under his list of prepared spells.
pg. 170 - House Captain -
The NPC is short 4 hp. The writer gave him average hp for first level.
The NPC's saving throw line should list the Sadistic Reward feat as a potential modifier.
The NPC should have an SQ entry to indicate his ability to sense hidden doors when passing within 5 feet.
While the NPC's skill block adds up correctly, I'd lower his Knowledge (the planes) modifier by 1 while increasing his Knowledge (nobility) modifier by 1 so that he gains an additional synergy to Diplomacy checks (increasing the modifier from +18 to +20).
pg. 171 - House Wizard -
The NPC is short one language known.
The NPC is 3 hp short.
The NPC has not gained any bonus spells from a high Charisma attribute. Give him one additional spell per day of levels one through four.
The NPC's phantasmal killer and shout spells should have a DC of 18 instead of 22.
The NPC has one too many Advanced Learning spells. Delete either explosive cascade (3rd level) or battering ram (2nd level).
The attack bonus for the ice knife spell should be +15 ranged rather than +11 ranged touch.
The attack bonus for the chill touch spell should be +3 touch rather than +2 touch.
The NPC should have an SQ entry to indicate his ability to sense hidden doors when passing within 5 feet.
I have no idea from where the NPC gained the fiendish servant SQ. Delete the entry.
The NPC's Sudden Empower feat shoud be listed as a bonus feat.
I was gonna use some NPCs from this book a few weeks ago for a massive hack-n-slash dungeon I'm running on the side - good thing I passed on that. Guess I'll just stick to writing up my own NPCs like usual. Even though the PCs would be unlikely to notice any of these mistakes in the heat of combat, the truth is too sour for my taste.

Essex, you continue to rock my socks. Please tell me you've been hired to work on 4e? Who needs a resume when you have all these threads you've made? : )
Considering he works for minis (which, last I heard, he never received), I'd say they'd get their money's worth if they hired him.
Sadly, I never received the minis that I was promised for providing errata for the Magic Item Compendium. On the other hand, since my personal situation has changed since last summer, I am now capable of relocating if the prospective job pays enough to live on (and given my lack of vices other than RPG's and comic books, I can live relatively cheaply). [If anybody at WotC is interested, I have college degrees in Communications and English and spent a decade as a proofreader for a subsidiary of a national media organization].

Here is the last of the errata for the sample drow. I'll be reading through the Drow Adventures next, and providing errata for the few stat blocks in the section.

pg. 172 - Spider Sentinel -
The NPC is short 4 hp. The writer gave him average hp for first level.
The NPC's Speed entry should probably indicate his woodland stride class feature.
The NPC's Manyshot ranged attack entry should change from +9/+9/+9 (1d6+2/x3 + poison) to +11 (1d6+2/x3 + poison & 1d6+2 [no threat range] + poison).
The NPC's Rapid Shot ranged attack entry should change from +13/+10/+13 to +13/+13/+8.
One of the NPC's attributes should be raised by 1 point to account for his 8th level ability increase. I'd put it into Wisdom so that he can use his 1st level spell slot.
The NPC's wild empathy SQ should be +13 (+9 magical beasts) due to the bonus from his Handle Animal skill synergy.
The NPC should have an SQ entry to indicate his ability to sense hidden doors when passing within 5 feet.
The NPC's skill block should note his Knowledge (nature) modifier of +2 (+0 Int +2 synergy) and that he can only use the skill to make DC 10 checks.
The NPC's skill block should probably note that some skills are modified by his favored enemy class feature.
The NPC's vermin companion is too powerful. A 9th level Ranger has an animal companion as if he were a 4th level Druid. Since choosing a large monstrous spider as a companion decreases your effective level by 3, the NPC should be considered the equivalent of a 1st level Druid. Replace the vermin companion with the one from page 289 of the Monster Manual, and grant it the link and share spells SQ.
Sorry for the month long wait for more errata, but my current temp job is nearly two hours away. Spending twenty hours a day traveling to work, working, traveling from work, or sleeping leaves very little time to provide errata; especially when I'm also writing articles as a freelance reporter for the local newspaper during my limited free time. What little time I have left is eaten up by recreational reading and participation in Steve Jackson Games' open beta test of the online UltraCorps game (my little empire currently consists of seven worlds, and will likely add an eighth in two rounds).

Here is a bit of errata, expect more to come slowly:

pg. 174 - Gaelimor Zyrshaen -
The NPC is two hp short.

pg. 174 - Keveras Lorakythe -
The NPC is three hp short.

pg. 174 - 2 Drow Arcane Guards -
The entry indicates that the NPC's are CR 5 and have 19 hp. The entry that the text refers to indicates that they are CR 8 and have 35 hp.

pg. 174 - 3 Greater Quaggoths -
The creatures have 10 hp too many.
pg. 175 - The stated Encounter Level of 11 or 12 is too low. I believe that the encounter should actually be EL 12 or 13.

pg. 176 - 2 Bugbear Overseers -
The creatures has 1 hp too many.

pg. 178 - 5 Violet Fungi -
The damage entry should change from 1d16+2 to 1d6+2.

pg. 178 - How does an encounter consisting of a CR 15 creature and 5 CR 3 creatures gain an EL of 14?

pg. 178 - Phazeuroth -
The creature is 100 hp short.

pg. 178 - The last sentence on the page indicates that if the sounds of battle are MAGICALLY SILENCED, a Druid will come to investigate the noise?

pg. 179 - 3 Szarkai Fighters -
The NPCs are 4 hp short because they were only given average hp at first level.
Spell-like abilities do not suffer from arcane spell failure due to armor.
The NPCs have ability score adjustments that add up to at least a 29 point build. This is 4 points above the elite array.
The NPCs should have an SQ entry to indicate their ability to sense hidden doors when passing within 5 feet.
The NPCs should have Climb modifiers of -3 instead of -5 (0 ranks +4 Strength bonus - 5 masterwork armor penalty - 2 heave steel shield penalty).
The NPCs should have Jump modifiers of -9 instead of -5 (0 ranks +4 Strength bonus - 5 masterwork armor penalty - 2 heave steel shield penalty - 6 speed penalty).

pg. 180 - Szarkai Druid -
The NPC has Terran as a bonus language. Neither Drow nor Druids gain Terran as a bonus language.
The NPC is 8 hp short.
A wounding weapon inflicts one point of Constitution damage rather than two.
The NPC has ability scores that add up to well beyond even a high-powered campaign point buy while his Charisma is so low that it isn't even on the point buy chart.
The NPC should have an animal companion with him, as the companion is an integral part of the CR of a Druid encounter.
The NPCs should have an SQ entry to indicate their ability to sense hidden doors when passing within 5 feet.
The Combat Casting feat should provide a situational modifier to be listed after the Concentration skill.
The skill block should account for the +2 synergy to default Appraise checks made to appraise alchemical items.
The skill block should account for the +2 synergy to Survival checks made in underground and aboveground environments.
The skill block does not add up properly. Reducing the NPC's Hide and Listen modifiers by 1 point each corrects the problem.
The NPC does not have the material component for a Stoneskin spell among his possessions.

pg. 180 - 3 Violet Fungi -
Several sections of text preceding this entry indicate that there are two violet fungi, but the entry indicates that there are three.
pg. 180 - The EL of the Chapel of Lolth should be 13 instead of 14 according to page 49 of the DMG.

pg. 181 - 2 Dread Fangs of Lolth -
The NPCs should have a CR of 11 instead of 13; their EL would be 13.
The NPCs are 3 hp short.

pg. 182 - The EL of the Main Entrance should likely by 12 instead of 11.

pg. 182 - Troll Filth-Eather -
The creature's hp are wrong whether it is raging or non-raging.

pg. 183 - Troll Tunnel Thug -
The creature has 45 hp too few.

pg. 183 - Drow Assassin -
The NPC is short 3 hp.

pg. 183 - I believe that the EL of the Guard Tower should be 11 instead of 10.

pg. 184 - 3 Bugbear Stonejacks -
The NPC's are all short 7 hp.

pg. 184 - 2 Arcane Guards -
The NPC ability scores are too high for the Elite Array. In order to meet the Elite Array, lower their Strength from 13 to 12.
The NPCs should have familiar listed as an SQ.
The NPCs should have an SQ entry to indicate their ability to sense hidden doors when passing within 5 feet.
The NPCs are two skill points short. Give them each 2 ranks in Knowledge (arcana) for a total modifier of +5.
I wonder why the writer didn't bother to use the Drow Fighter alternative class feature from this book. The arcane guards are never going to use heavy armor or tower shields anyway, so they may as well gain a free +2 to initiative and a bonus to certain damage rolls.
Almost to the end (finally). Here are some more pieces of errata and some comments.


pg. 188 - The Blood of the Spider Queen site indicates that it can grant its abilities to male clerics of Lolth, but Lolth only accepts female clerics.

pg. 198 - The high priestess at the Temple of Nerull is indicated as being both a half-fiend drow and the daughter of a human and a demon. Since I doubt that the drow would tolerate a drow cleric openly serving a non-drow diety, I'd change the initial entry to half-fiend human.

pg. 198 - While not an actual error, the Temple of Vecna entry indicates that it is full of subterranean passages. This is a redundant statement as the entire city is subterranean.

pg. 202 - While not an actual error, the Poisons and Potions entry indicates that the shop is filled with swarms of adamantine spiders. The owner seems to be one level short of being able to create adamantine spiders. Either he buys them from others or he has a feat that increases his caster level high enough to create the constructs.

pg. 209 - Because the CR of two of the NPCs are a point too low, I believe that the ECL of the Slaver Attack should be increased from 8 to either 9 or 10 (probably 9 since they are penalized by trying to capture the PC's alive).

pg. 210 - Valma Phar'aen -
The CR of the NPC is one point too low.
The NPC's AC entry should include a reference to his trap sense class feature.
The NPC is short 2 hp (they gave him average hp at first level).
The NPC's saving throw entry should include a reference to his trap sense class feature.
The NPC's +2 rapier should inflict 1d6+4 damage instead of 1d6+2.
The NPC's mwk dagger should inflict 1d4+2 damage instead of 1d4.
The NPC should have an SQ entry to indicate his ability to sense hidden doors when passing within 5 feet.
Two of the NPC's feats should be listed as bonus feats from his fighter levels.
The NPC has 5 skill points too many. As the NPC's Hide skill is 2 points higher than is possible for a character of his level, I assume that he originally had a drow version of the cloak of elvenkind. Either lower his Hide modifier by 5 or give him back the cloak.

pg. 210 - Jhael'min Phar'aen -
The CR of the NPC is one point too low.
The NPC's AC entry should include a reference to her trap sense class feature.
The NPC is short 3 hp (they gave her average hp at first level).
The NPC should have a resist entry of evasion.
The NPC's saving throw entry should include a reference to her trap sense class feature.
The NPC's mwk dagger should have a melee attack roll of +4 instead of +3.
The NPC's mwk dagger should inflict 1d4-1 damage instead of 1d4+1 in both the melee and ranged entry.
The NPC's attack options should include sneak attack+2d6.
The CL of the NPC's spell-like abilities should be 5 instead of 6.
The NPC's ability scores add up to 28 instead of being equivalent to the 25 point elite array that is standard to NPCs.
The NPC should have an SQ entry to indicate her trapfinding class feature.
The NPC should have an SQ entry to indicate her trap sense class feature.
The NPC should have an SQ entry to indicate her familiar class feature.
The NPC should have an SQ entry to indicate her ability to sense hidden doors when passing within 5 feet.
The NPC is 6 skill points short. Give her 6 ranks of tumble (total modifier +8) and apply a +2 bonus to Balance (total modifier +8) and Jump (total modifier +1) because of the new Tumble synergy.
The NPC's Concentration skill should include a situational modifier because of her Combat Casting feat.

pg. 211 - 6 Bugbears -
The melee attack entry should be +4 instead of +5. It should then be reduced by another 4 (to +0) if they wish to do nonlethal damage so as to capture the characters.
The ranged attack entry should be +3 instead of +5 and should be a ranged touch attack.
The creatures are three skill points short. Raise their Climb, Hide, and Move Silently modifiers by 1 point each to account for the fact that, unlike the Bugbears from the Monster Manual, they are not suffering from armor check penalities from using shields.

Note - If you want the encounter to be optimized for a slaver attack that actually has a reasonable chance of capturing somebody, then make the following changes:
1). Change the first Bugbear feat from Alertness to Martial Weapon Proficiency (sap). Lower their Listen and Spot modifiers by 2 and replace their clubs with saps.
2). Change the male Drow's +2 rapier into a +2 sap.
3). Change the female Drow's melee entry for a mwk dagger into an entry for a mwk sap.
4). Change the female Drow's first level spell from Magic Missle to Ray of Enfeeblement.
WOOT! I have finally, after owning the book for nearly a year, finished with the errata and sarcastic comments. Here is the last batch:

pg. 211 - Necropolis Square -
The EL should be 8+ instead of 6+ if you assume a minimum of 12 ghouls.

pg. 211 - 12+ Ghouls -
The Ghouls should have Charisma scores of 12 instead of 1.
The Ghoul fever and paralysis entries should indicate that the saving throws are Charisma based.

pg. 220 - The last sentence before the heading RACIAL CLASS FEATURES states "For more details on drow, see MM 103." Let me get this straight, a book entitled Drow of the Underdark refers you to a half page entry in the Monster Manual for information on drow? Why not have the text "For more details on drow, see the previous 219 pages of this book"?

pg. 221 - Drow Base Traits -
Drow made using this system seem to lack the typical drow proficiency with hand crossbow, rapier, and short sword. Add proficiency in these weapons.
Kuo-Toan is listed as a bonus language despite the fact that it is not listed as a bonus language on page 36. Since it was listed as a bonus language in the Monster Manual you can either assume that it was accidentally left off of page 36 or that it was purposefully removed but that this section did not take the change into account.