Combining Dave Hargrave’s gonzo, over-the-top Arduin Grimoires with the rigorous, simulationist campaign structures of Alexander Macris’s Adventurer Conqueror King System II (ACKS II) turns chaotic high-fantasy into a highly functional campaign world.
System Synergies & Design Mechanics
Integrating these two Old School Renaissance (OSR) titans requires blending ACKS II's macro-level mechanics with Arduin's micro-level combat lethality and techno-magical strangeness:
Domain Mechanics vs. Technomagic: ACKS II provides strict rules for population investment, land clearing, trade routes, and stronghold revenue. Arduin injects technological oddities (e.g., power cells, glass-steel weapons, phantasmal engines). In an ACKS II framework, Arduin artifacts can be treated as Domain Special Resources that grant bonus revenue, reduce stronghold upkeep, or act as siege engines.
Mortal Wounds & Arduin Criticals: ACKS II uses a structured Mortal Wounds table to determine character fate upon reaching 0 HP. You can seamlessly map Arduin’s iconic Critical Hit & Fumble Charts directly into ACKS II's combat flow: natural 20s force an immediate roll on the Arduin Critical Hit table, overriding standard weapon damage while keeping ACKS II's cleave and combat maneuver rules intact.
Class & Race Integration: Standard ACKS II relies on strict race-as-class templates (e.g., Elven Spellsword). Arduin’s unique races—like the insectoid Phraint, reptilian Saurig, or heavy Amazonian Skynauts—can easily be built using ACKS II's Custom Class Creation Engine by assigning hit die steps, fighting value, and special racial proficiencies.
Detailed Monster Conversion: The Phraint Soldier
To demonstrate direct system conversion, here is a complete stat block for Arduin’s iconic mantis-like warrior built directly into ACKS II mechanics.
Armor Class: 5 (Exoskeleton + Agility, equivalent to ACKS II Scale)
Hit Dice: $3d8+3$ ($16 \text{ hp}$)
Attacks: 2 × Leaping Claws ($1d6$) or 1 × Arduin Glass-Steel Longsword ($1d8+2$)
Save: Fighter 3
Morale: +2
Alignment: Neutral
Movement: 120' (40') / Leaping 180' (60')
ACKS II Fighting Tier: Tier 2 (Cleaves up to 3 times per round against $1\text{-HD}$ foes)
Special Traits (Arduin/ACKS II Combined):
Spring Jump: Can leap up to 60 feet into combat, ignoring frontline positioning to directly engage backline spellcasters. Grants +2 to Hit on the turn it leaps.
Chitinous Resilience: Immune to non-magical sleep, hold, and mind-affecting effects.
Glass-Steel Equipment: Weapons ignore 1 point of enemy Armor Class and never break on critical fumble rolls.
The Phraint is Arduin’s iconic insectoid warrior—a tall, sleek, mantis-like humanoid built for blinding speed, vertical leaps, and relentless precision. Using the ACKS II Custom Class Creation Engine, this class combines martial prowess, natural armor, high mobility, and insectoid traits.
Class Build Mechanics (ACKS II Engine)
Base Race: Phraint (Custom Demi-Human Base)
XP to Level 2: $2,200 \text{ XP}$
Hit Dice: $1d8$ per level (up to Level 9, then $+2 \text{ hp}$ per level)
Maximum Level: 14
Category Point Allocation
Demihuman (Phraint): 1 Category Point
Traits: Chitinous Exoskeleton ($AC\ 4$ base, equivalent to scale armor), Spring Leap, Insectoid Mind (immune to Sleep and Charm), Compound Vision ($120\text{'}$ Darkvision, $-2$ chance to be surprised).
Fighting: 2 Category Points
Combat Progression: Fighter/Martial attack throws ($+1$ to hit every 2 levels).
Weapon Skills: Broad access to melee and missile weapons.
Cleaves: $1$ Cleave per level up to character level (max $14$).
Magic: 0 Category Points (Non-caster)
Thievery: 1 Category Point
Skills: Acrobatics, Stealth, and Climbing progression.
Phraint Level Advancement Table
| Level | Experience | Hit Dice | Attack Throw | Save | Cleaves/Rnd | Special Abilities |
| 1 | $0$ | $1d8+1$ | $10+$ | $14+$ | $1$ | Exoskeleton ($AC\ 4$), Spring Leap, Compound Vision, Insectoid Mind |
| 2 | $2,200$ | $2d8+2$ | $9+$ | $13+$ | $2$ | Uncanny Dodge |
| 3 | $4,400$ | $3d8+3$ | $8+$ | $12+$ | $3$ | Martial Proficiency |
| 4 | $8,800$ | $4d8+4$ | $7+$ | $11+$ | $4$ | Precise Strike ($+1$ Damage) |
| 5 | $17,600$ | $5d8+5$ | $6+$ | $10+$ | $5$ | Bound Leap (Double distance) |
| 6 | $35,200$ | $6d8+6$ | $5+$ | $9+$ | $6$ | Chitin Hardening ($AC\ 5$) |
| 7 | $70,400$ | $7d8+7$ | $4+$ | $8+$ | $7$ | Pounce Attack |
| 8 | $140,800$ | $8d8+8$ | $3+$ | $7+$ | $8$ | Martial Proficiency |
| 9 | $280,000$ | $9d8+9$ | $2+$ | $6+$ | $9$ | Hive Commander (Establish Hive-Fortress) |
| 10 | $400,000$ | $9d8+11$ | $1+$ | $5+$ | $10$ | Precise Strike ($+2$ Damage) |
| 11 | $520,000$ | $9d8+13$ | $1+$ | $4+$ | $11$ | Chitin Hardening ($AC\ 6$) |
| 12 | $640,000$ | $9d8+15$ | $1+$ | $3+$ | $12$ | Martial Proficiency |
| 13 | $760,000$ | $9d8+17$ | $1+$ | $2+$ | $13$ | Apex Predator (Immune to Fear) |
| 14 | $880,000$ | $9d8+19$ | $1+$ | $2+$ | $14$ | Master of the Hive |
Class Features & Racial Traits
Chitinous Exoskeleton: A Phraint's natural armor grants an base $AC\ 4$ at Level 1 (does not stack with worn body armor, but shield modifiers apply). Increases to $AC\ 5$ at Level 6, and $AC\ 6$ at Level 11.
Spring Leap: Once per turn, a Phraint can leap up to $60\text{'}$ forward or $30\text{'}$ vertically as part of a movement action. This bypasses frontline terrain and enemies to reach backline targets.
Compound Vision: Wide-angle multi-faceted eyes grant $120\text{'}$ Darkvision and a $-2$ bonus to surprise rolls (surprised only on a $1$ on $1d6$).
Insectoid Mind: Alien biology renders Phraints completely immune to Sleep, Charm, and non-magical morale effects.
Pounce Attack (Level 7): When executing a Spring Leap directly into an attack, the Phraint gains $+2$ to hit and deals double damage on the initial strike.
Hive Commander (Domain Level 9): Upon reaching 9th level, a Phraint may clear a hex and construct a subterranean or spire-like Hive-Fortress. Attracts $2d6 \times 10$ Phraint warriors (Level 1–2) and $1d4$ elite Phraint captains (Level 4–5) as a loyal garrison.