As an inveterate tinkerer, I’ve developed a ton of house rules for ACKS over time. Here are the ones I’m using for my Black City campaign. Class descriptions (including custom classes) can be found on the Black City Class Summary.
Ability Scores: Minor tweaks from the Heroic Fantasy Companion and forum discussion:
A character’s Strength bonus or penalty also applies to hurled missile weapons, such as javelins and hand axes. (But not to projectile weapons.)
A character’s Wisdom bonus or penalty applies to all saving throws. (Not just saves vs. spells or magic items.)
Thievery Skills: I am not using the adventuring equipment from the Heroic Fantasy Companion (except maybe as “magical” items), nor am I using the Dexterity modifiers or encumbrance rules from the Heroic Adventures chapter.
Instead, the Thievery Skills table (ACKS Core Rules p.23) is revised as follows:
There are adjustments to a few non-Thief proficiencies as well:
Missile Attacks into Melee: When shooting into melee, the character can either shoot wildly (roll normally to hit, target is determined randomly by referee) or – if the target is at short range – take an aimed shot. Aiming allows the attacker to select his target, but the attack throw is made with a a -4 penalty. If a natural 1 is rolled on the attack throw, the shot hits an unintended target (selected by the referee).
The Precise Shooting proficiency is revised as follows:
Precise Shooting: This proficiency reduces the missile attack penalty against opponents engaged in melee by 2. In addition, the character will not hit unintended targets when taking an aimed shot at short range, even on a roll of natural 1. Selecting this proficiency a second time eliminates the missile attack penalty entirely.
Backstab & Armour: Characters wearing armour heavier than leather are restricted to ×2 damage on a successful Backstab.
(This is just like the Ambushing proficiency. The Core ACKS RAW do not permit Backstab attacks at all in armour heavier than leather.)
Proficiencies: The following house rules are my own:
Wakefulness and Unarmed Fighting are added to the General Proficiency List. (I want a “Night Watchman” option without invoking elves. And more street brawlers are always good.)
Surgery hasn’t been invented yet, so Healing is restricted to 2 ranks (Physicker).
In addition to granting fluency, the Language proficiency increases the character’s literacy level by one ‘step’. (from Illiterate to Semi-Literate, or Semi-Literate to Literate. Or a low-INT character can select the proficiency to gain full literacy instead of a new language.)
Fiddly Encumbrance Rule: Here’s an obscure one from D@W that is discussed on the forums. I’ve extrapolated the encumbrance thresholds for for low-STR characters as well:
STR 3 (-3): 4/6/8/17
STR 4-5 (-2): 4/7/9/18
STR 6-8 (-1): 5/7/9/19
STR 9-12 (+0): 5/7/10/20
STR 13-15 (+1): 5/8/10/21
STR 16-17 (+2): 6/8/11/22
STR 18 (+3): 6/9/11/23
Where each value is the max weight in stones for a given movement rate (120’/90’/60’/30′).
Fighter Trade-Offs (Custom Classes): Fighter Trade-Offs for custom classes are only 125XP instead of 150XP (see ACKS Player’s Companion, p.79).
This decreases slightly the base XP for a number of Fighter subclasses, which I’ve included in my Black City Class Summary and the relevant class descriptions.