On page 97, update the example below to reflect that the correct spotting distance is 105 yards, not 102 yards.
EXAMPLE: Adventurers encounter a 12’ tall ettin in a light forest. The base encounter distance is 5d8 yards, and the Judge rolls a 21, yielding 21 yards. However, the ettin is double the height of a man, so the encounter distance is doubled to 42 yards. If the adventurers were standing on a 24’ hill (four times the height of a man), the encounter distance of 21 yards would multiply by (4+1) five times, to 105 yards.
On page 26, the Assassin (Fighter) Attack and Saving Throws should progress at a rate of 2 points points every 3 levels, not 2 points every 4 levels.
On p. 41, under Catapults and Ballista, the weights of heavy and light catapults are reversed. Heavy Catapults weight 1,800lb while Light Catapults weigh 1,200lb.
I think there’s an error on page 209. The chart for ornamental special treasure asks for a roll of 1d8 but offers results for rolls higher than 8. (It looks copied from the chart for platinum pieces.)
Not sure if this is errata or I am misunderstanding something but: on page 104 under Damage it states unarmed attacks deal 1d2 damage and then on page 109 under Brawling it says normal characters do 1d3 with a punch.
On p. 57, Elven Nightblade Proficiency List, remove Arcane Dabbling. Add Combat Trickery (disarm).
On p.104, under Damage, it incorrectly states that “unarmed strikes deal 1d2 damage.” Unarmed strikes deal 1d3 nonlethal damage with a punch or 1d4 nonlethal damage with a kick, as stated on p. 109.
On p.60, under Elven Bloodline, it states that the character’s “lifespan is three times longer than normal for his race.” Human NPCs without Elven Bloodline live to an average of 66 years, and with Elven Bloodline live to an average of 200 years. Human PCs should use the table for elves under Character Aging on p.248 of ACKS.
On p.164, under Primary Dragon Attributes, dragons of Very Old, Ancient, and Venerable age are listed as saving as F16, F18, and F20. These saving throws are intended to be interpolated by increasing the Fighter saving throws by 2 points per 3 levels.
For example, Petrification & Paralysis:
14-15 6+
16 5+
17-18 4+
19 3+
20-21 2+
For simplicity, F16 is simply F14 +1; F18 is F14 +2; and F20 is F14 +4.
The language for bard proficiencies should be revised so as not to preclude same-sex attraction:
Magical Music proficiency (page 62): “The character can perform music that can serenade those who are potentially attracted to the character (as a charm person spell) or tame savage beasts (as a sleep spell).”
Seduction proficiency (page 63): “The character is either naturally alluring or a practiced seducer. He always receives a +2 bonus on reaction rolls with others who are potentially attracted to the character.”
On p.56, Bladedancer Proficiency List, Combat Trickery, trip should be knock down (I believe).
On p230, “Adjusting Population Density”.
You have: “The size of the realm can be increased if the Judge wants a world with a lower population density is lower.”
Should be: “The size of the realm can be increased if the Judge wants a world with a lower population density.”
Also, the tables on p230 “Realms by Type” and p231 “Revenue by Realm Type” both list a Kingdom as having “364K–2,000K” families. I assume by 2,000K you mean 2M, right? But on both tables, an empire has a lower bound of 1.5 million families. No other realm type has a lower bound lower than the next smaller type’s upper bound. So is this correct, or is a kingdom’s max size smaller than 2 million families, or is an empire’s min size larger than 1.5 million?
On page 193, SNAKE, Giant Python
In the stat block, the constriction damage is listed as 2d8. In the descriptive text it’s 2d4. The stat block is correct.
On page 196, STATUE, ANIMATED
Because all of them have the special ability of being immune to poison, charm, sleep, and hold spells, all their HD entries be marked with an asterisk (and the Iron statue with two asterisks because it also magnetizes weapons) like the skeleton and zombie undead entries are for the same immunities.
Following this, the XP totals need revising to:
Crystal 65
Stone 350
Iron 190
That’s not an error. That’s simply how the math works out. A small empire has 4x4x4x4 subdomains, while a large kingdom has 6x6x6x6x6 subdomains.
When examining Combat Trickery for a fighter, I was making, I noticed “wrestling” wasn’t on the list. Don’t know if that is intentional or not.
In the Index, both Intelligence and Languages point to p. 226, which is incorrect. I believe this should be p. 17. Also, I suggest adding Literacy to the Index, same p. 17.
Not quite errata and it might be solved elsewhere in Autarch land but my beer-soaked hardcover has “Vermin” listed as the page sub-headers in most of the monster section.
In the Monsters section, the triceratops description discusses its ability to charge twice:
“If a triceratops has enough distance between it and its foe, it will commit to a charge to score double damage with its gore attack.”
“When distance permits, a triceratops may charge with its gore attack to deal double damage.”
I don’t know if this is errata but it sure is funny!
On p.249 of ACKS on the monster poison table there is listed a “Giant Crap Spider” 
On page 226, on the chart under Sentient Weapon Motivations, the result for a roll of 1 is blank.