ACKS Piledrivers

So what's a piledriver in an ACKS context?

From Critical Hits:

Piledriver is the term we use for every time an unintentional rules mistake is made during play and not corrected.  Catching someone going out of order is not piledriver.  Small Piledrivers are mostly ignored, such as messing up a single timing issue during a Magic Draft during the first round of play.  Other games are so finicky we end up Piledriving them into oblivion.  I daresay I’ve never played a game of Twilight Imperium that did not end up as a massive Piledriver.  For games that we play infrequently, it’s a common occurrence to midway through the game have someone rifle through the rule book and cry out, “PILEDRIVER!”

And boy, did I find some piledrivers from previous campaigns in a re-read of the ACKS rules.

By section, in order of descending priority:

Adventures:

• Torches and lanterns generate 30' of good light, and another 20' of shadowy illumination
• Characters or monsters that carry a light source are unable to surprise opponents (!).  Being blind or in darkness is only -4 to hit, though, which is...  bad, but not as bad as being blinded in 3.x.  Blind Fighting proficiency ++, especially for thieves and assassins.
• Dwarves hear noises on 14+; not sure if this is correct, as it's not in the Characters section.
• Encounter distance in dungeons is 2d6*10 feet.  That's a long(er) way.
• The Surprise and Sneaking section on page 97 is really interesting, especially to anyone wanting to play a thief.  I suspect we derped on thieves more thoroughly than we realized.
• Reaction rolls apply the Charisma bonus of the "lead" character.  Whether this means in front of the marching order or on top of chain of command is unclear.  If front of marching order, then some interesting risk management comes into play and "thief out front" becomes more viable.  Also limits the power of Diplo, Intimidate, Mystic Aura, &c unless you're willing to put yout butt out on the line.
• Page 101, top left has a paragraph on closing attacks, providing yet another reason that Spears Are Awesome.
• Helpless targets can be automatically slain only if the attacker is unengaged.  Ghouls are now less deadly, as is Sleep.
• Wielding a magic weapon in your off-hand provides its magic bonus to hit, but not to damage.  We figured this one out eventually.
• Oil spread on the ground covers a 5' diameter, not radius.
• Misses with thrown oil scatter.
• Spellcasters may not move and then cast (!).  Web is now significantly harder to use effectively as a Mage.  Great for a 2nd-row spellspear, though.
• Page 113 has rules for swimming and drowning.  We missed them before, and should have all drowned as we were running aground in Alex's game.
• Seafaring may get houseruled to provide a bonus on swimming rolls.

Spellcasting:

• Eight hours of uninterrupted rest, plus an hour of meditation or prayer, are required to restore spell slots.  Midnight sharkipede attacks are no good for wizard's beauty sleep.
• Cancelling spells mid-cast without burning slots is probably not good for game balance.  I don't know where we got this idea, but it was not our best.
• Again, no other actions in a round when you're casting.
• When levelling, an arcanist's master only provides new spells up to the number he can cast per day, rather than his max repertoire.  The wizard's quest for knowledge is suddenly intensified.
• Note that arcanists starting at higher than 1st level fill their repertoire during character generation.  Just not when levelling further.
• Spell signatures.  We didn't has them.

Characters:

• Bard inspire courage doesn't say it can't be used during combat; it says it provides no bonus to "characters who are already engaged in combat."  If we take this to mean the same thing as "engaged" does in the Adventures chapter (within 5' of an opponent), then it's way more useful than it used to be.  Bless is too, come to think of it.
• Vaultguards and Furies cannot use human-sized two-handed weapons.  This has been clarified on the fora to mean that they can use dwarf-proportioned two-handed weapons, at -1 init and 1d10 damage as normal.
• The Adventuring Parties rules don't actually require parties to have a name :(

Equipment: 

• The Standards of Living table is a good motivator towards going out and dungeoneering despite the fact that a character is laid up with a mortal wound (also makes Craft and Profession profs slightly more useful).  Still gotta pay the bills.  We failed to notice this table, as we've done before with Standards of Living tables in, say, Traveller.

Proficiencies:

• You can hold off on selecting your general proficiencies from +Int until they're needed during play.  We did this with languages, but missed it for profs.
• Healing doubles the natural healing rate of patients, but there's a limit on number of patients per day that we missed.
• Mimicry lets you mimic "animal calls and foreign language accents."  Dragons may or may not fall under "animals" for this purpose.
• Sensing Power and Evil each take a turn to use.

Campaigns: Mistakes were made, but willfully rather than out of ignorance of the rules.