OSR Redo & Recon Converting Adapting EX2: The Land Beyond the Magic Mirror to Adventurer Conqueror King System II (ACKS II)

 Adapting EX2: The Land Beyond the Magic Mirror to Adventurer Conqueror King System II (ACKS II) works remarkably well because ACKS II is built to support name-level domain play (Levels 9–12), rigorous wilderness/hexcrawl procedures, and codified magical research/planar mechanics. This module picks right up from 

OSR Redo & Recon Converting and expanding Dave J. Browne and Don Turnbull  classic module U1: The Sinister Secret of Saltmarsh into Adventurer Conqueror King System II (ACKS II)

Instead of treating EX2 as a whimsical one-off, ACKS II allows you to run it as a high-stakes extradimensional sub-sandbox—a pocket dimension (or "sinkhole of chaos/magic") anchored to an archmage's sanctum where Conqueror-tier characters can harvest rare magical components, recruit bizarre planar henchmen, or claim an extradimensional domain.

1. Structural & Hexcrawl Conversion

In EX2, the world is an 8x8 chessboard divided by brooks and hedges. In ACKS II, translate this directly into a micro-hexcrawl using standard wilderness procedures:

• Scale & Movement: Treat each square on the 8x8 board as a 1-mile square (or standard 6-mile hex if you want multi-day provisioning to matter). Every time the party crosses a brook or hedge into a new square, it costs 1 exploration turn (or 1/4 day of wilderness travel) and triggers a Planar Event / Chess Shift.

• Lateral Inversion & Combat Penalties: Stepping through the mirror reverses left and right. Until a character spends 1 full turn acclimating (or passes an Intuition / Intelligence check at -2, or a Save vs. Spells), they suffer a -2 penalty to attack throws and +2 penalty to AC (worse AC in ascending ACKS II terms; or -2 to AC) due to reversed weapon/shield hands. Written scrolls and spellbooks brought from the prime material plane appear mirrored and require a read magic spell or 1 turn of careful decoding to use.

• The 8th Rank Promotion: Just like a pawn reaching the back rank in chess, any character who traverses from Rank 1 to Rank 8 across the board undergoes an Arcane Transmutation (Save vs. Spells to resist, though most will want to accept it):

  • Fighters/Martial Classes: Gain the title of Knight of the Looking-Glass, granting a permanent +1 bonus to Morale for all followers and a +1 magic lance/barding set.

  • Mages/Elves: Gain immediate mastery of one random 4th- or 5th-level spell formula directly into their repertoire, plus 1,000 gp worth of special spell-research components.

  • Clerics/Thieves: Gain a permanent +2 bonus to reaction rolls with planar/fey entities and a cloak of displacement (or ring of blinking).

2. ACKS II Monster & Faction Conversions

ACKS II uses Ascending Armor Class (AC) (Base 0 unarmored, leather +2, chain +4, plate +6), Attack Throws (target 10+ for 1 HD, scaling down by 1 per ~1-2 HD), and 5 Saving Throw Categories (Petrification/Paralysis, Poison/Death, Blast/Breath, Staffs/Wands, Spells).

Apex Planar Predators

Creature	AC	HD	Move	Attacks	Damage	Save	Morale	Special Abilities (ACKS II)
Jabberwock	9	14*	120' / 240' Fly	2 claws / 1 bite / 1 tail	2d8 / 2d8 / 4d6 / 2d10	F14	+3	Burbling Breath: 60' cone, 6d8 sonic/confusion damage (Save vs. Blast for half; failure causes confusion for 1d4 rounds). Vorpal Vulnerability: Takes double damage from vorpal blades; any natural 20 from a vorpal weapon decapitates instantly regardless of HD.
Bandersnatch	7	10*	180'	2 claws / 1 bite	2d6 / 2d6 / 3d8	F10	+2	Frumious Ambush: Surprises on 1–4 on 1d6. Snatch & Drag: If both claws hit, target is pinned (Save vs. Paralysis to escape) and dragged at full movement.
Jubjub Bird	6	8	60' / 210' Fly	2 talons / 1 beak	1d8 / 1d8 / 2d8	F8	+1	Shriek: Once per combat, all within 60' must Save vs. Paralysis or drop held items and flee for 1d3 rounds.

Notable NPCs & Court Forces

• Tweedledum & Tweedledee (Twin Fighters): Treat as 9th-level Fighters each (AC 8 in patchwork tin/pot-helm plate, HD 9, Attack Throw 4+, Damage 1d10+3 with oversized fire-irons/clubs, Morale +2). If reduced below 25% HP, they summon the Monstrous Crow (AC 5, HD 12, 240' Fly, wing buffet forces Save vs. Paralysis or knocked prone and blinded by darkness for 1d4 rounds).

• The Red & White Queens (Planar Arch-Fey / Sorceresses): Treat as 11th-level Mages (AC 4 via protective wards, HD 11, Save M11).

  • Red Queen: Moves at 240' per turn (haste effect constantly active). Can issue a Command ("Off with their heads!") 3/day as a 5th-level spell effect (Save vs. Death or suffer 6d6 damage and forced retreat).

  • White Queen: Perpetually disheveled; casts reverse gravity, wall of force, and dimension door at will, but loses 1 round every 1d4 rounds to frantic, distracted muttering.

• Humpty Dumpty (Planar Lore-Broker): AC 2, HD 6, Save M9. Perched on a 20' narrow wall. Holds the exact linguistic key to the mirror's exit command. If knocked from the wall (any physical blow or failed balance check), he shatters in a 40' radius arcane detonation (8d6 force/blunt damage, Save vs. Blast for half) and cannot be reassembled even by a wish.

3. ACKS II Planar Mechanics & Magic Rules

In ACKS II, magic interacts heavily with planar boundaries and arcane research. Apply these four environmental rules across the 8x8 board:

1. Teleportation & Summoning Bounce: Spells like dimension door, teleport, and conjure elemental do not function normally. When cast, roll 1d8 to determine a random cardinal/diagonal direction—the spell lands 1 square (1 mile) off-target in that direction.

2. Retroactive Cause-and-Effect (White Queen's Squares): In squares controlled by the White Court, effects precede causes. When a character triggers a trap or fails a saving throw, they take the damage or condition 1 round before the visible hazard appears. If they subsequently prevent the trigger on their next turn (e.g., disarming the trap or slaying the attacker before it strikes), the damage is immediately healed.

3. Size-Shifting Groves (Eat Me / Drink Me Caches): Scattered across the board are crystal vials and mushroom rings. Consuming them triggers a growth or shrink effect (Save vs. Spells to negate) that alters character scale by a factor of 4x or 1/4x for 2d6 turns:

   • Giant Scale (4x): +4 to melee damage, +2 to STR checks, double movement rate, but cannot enter indoor structures and suffers -4 to AC against normal-sized archers.

   • Miniature Scale (1/4x): +4 to AC against normal-sized foes, +4 to Stealth/Hiding rolls, but weapon damage drops to 1d2 and movement drops to 30'.

4. Harvesting Special Components (ACKS II Spell Research): For Mages and Clerics, EX2 is a goldmine for ACKS II Magical Research and Magic Item Creation. Killing or harvesting from the plane's unique creatures yields high-value special components:

   • Jabberwock Heart / Vorpal Fang: Worth 4,500 gp toward researching or crafting vorpal weapons, shout, or confusion items.

   • Bandersnatch Hide: Worth 2,500 gp toward crafting boots of striding and springing or cloaks of elvenkind.

   • Looking-Glass Quicksilver (from the border mirror): Worth 3,000 gp toward crafting mirrors of mental prowess, crystal balls, or permanent planar portals.

4. Random Planar Encounter Table (1d12 per Square Shift)

Roll 1d12 whenever the party crosses a brook or spends an exploration turn searching a square:

d12	Encounter / Event	ACKS II Mechanical Effect
1	White Knight Patrol	1 clumsy 8th-level Fighter (AC 7, HD 8) mounted on a wooden-jointed warhorse. Falls off his horse on any attack roll of 1–5, but offers genuine hospitality and a map of 1d4 adjacent squares if helped up.
2	Red Rook Juggernaut	An animated, 15-foot-tall obsidian chess tower (AC 9, HD 12, Move 90'). Charges in straight orthogonal lines only; deals 3d10 crushing damage (Save vs. Paralysis to dive clear).
3	Snap-Dragonflies & Bread-and-Butterflies	A swarm of clockwork/confectionery insects (AC 4, HD 4). Non-hostile unless fire is lit; if ignited, the snap-dragonflies explode like fireballs (4d6 fire damage, 20' radius).
4	The Train (Looking-Glass Express)	A roaring steam locomotive bursts through the hedge line. Everyone in the square must pass a Save vs. Paralysis or be swept aboard and deposited 1d6 squares away in a random direction.
5	Tulgey Wood Whiffling	Thick, shifting mist blankets the square. Navigation checks suffer a -4 penalty; failing the check causes the party to loop back into the square they just left after 1 turn.
6	Bandersnatch Stalker	A single Bandersnatch (HD 10*) tracks the party from the tree line, waiting for a lone scout or rear-guard character to lag behind.
7	Fawn of the Forgetful Wood	A gentle planar deer (AC 2, HD 1) walks alongside the party. Anyone entering the grove with it must Save vs. Spells or forget their own name, class abilities, and prepared spells until they exit the grove.
8	Chess-Court Herald	A frog-footman delivers an official parchment summons from either the Red or White Queen. Accepting and attending the banquet grants +2 to Reaction Rolls with that court; tearing it up triggers a 3d6 lightning strike from the sky.
9	Pool of Backward Reflections	A calm pond showing the party's inverse selves. Drinking from it restores 2d8 HP (once per character), but reverses their alignment for 24 hours unless they pass a Save vs. Spells.
10	Tweedle-Brothers' Border Dispute	Tweedledum and Tweedledee block the brook bridge, demanding a toll of "one rattle, one poem, or three rounds of fisticuffs."
11	Jabberwock Shadow	No immediate combat—the Jabberwock passes overhead. Every character and henchman must make a Morale/Fear check (Save vs. Paralysis) or become shaken (-2 to all rolls for 1 turn).
12	Looking-Glass Cache	An abandoned pavilion containing 2d6 x 1,000 gp in platinum chess-pieces, 1d3 Growth/Shrink potions, and a scroll of Mirror Image and Dimension Door.

5. Integrating EX2 into an ACKS II Campaign

• Domain Hook (Levels 9+): If a party Wizard or Elf clears the Red and White Courts—or brokers a permanent stalemate between them—the 64-square chessboard can be claimed as a Sanctum / Extradimensional Domain. In ACKS II domain terms, it acts as a secure, concealed stronghold accessible only via the primary magic mirror, generating 1,500 gp/month in rare alchemical and planar components rather than standard peasant tax revenue.

• Henchman Recruitment: Allow the party to recruit surviving oddities—such as the White Knight (an eccentric 8th-level Fighter retainer who refuses to flee from battle) or a squad of 12 Pawn Guardsmen (1st-level heavy infantry in lacquered red/white plate)—provided they pay them in silver mirrors, poetry, or rare tea rather than standard gold coin.