It looks like a traveler, speaks like a sage, fights like a master swordsman — and the fireball you just threw at it will never work again.
Core Statistics #
| Stat | Value |
|---|---|
| Hit Dice | 8d8* (avg 36 HP) |
| AC | 13 |
| AV | 0 |
| HR | +8 |
| FR | +4 |
| FD | 15 |
| Move | 120 ft (40 ft encounter) |
| Attacks | 2 swords (1d8+4 / 1d8+4) OR fantastic device (see Special Attacks) |
| Save As | Fighter 8 |
| Morale | 10 |
| Treasure | Type V (individual; carried across planes) |
| Alignment | Any |
| CR | 11 |
| Size | Medium (variable — see Natural Polymorph) |
| Intelligence | High (INT 13) |
| XP | 1,200 |
AC/AV Reasoning #
The RC original is AC 9 (descending) — the worst possible unarmored AC. In ascending terms this is AC 11 base. However the Adaptor is an extraordinarily capable combatant with high DEX implied by its natural polymorph ability and planar travel. The conversion applies:
- AC 13 — AC 11 base + DEX modifier +2 (high DEX implied by fluid morphic physiology). The Adaptor wears no armor and carries AV 0 — it relies entirely on not being hit rather than absorbing damage. Its AC 13 represents a body that is constantly in slight motion, slightly off-angle, slightly not-quite-where-it-appears to be — a morphic body that makes precise targeting genuinely difficult without being supernaturally evasive.
- AV 0 — The Adaptor has no natural armor, scales, or hide worth noting. When it is hit, it is hit cleanly. This is the mechanical driver of its Adaptive Immunity — the creature’s survival strategy is to never take the same hit twice, not to absorb damage passively.
- Why not lower AC? The RC’s AC 9 (descending) is intentionally poor — the designers wanted the Adaptor to be hittable, making its Adaptive Immunity the interesting mechanical feature rather than a combination of high AC and immunity. This conversion respects that intent: AC 13 is reachable, AV 0 means full damage when hit, and the Adaptive Immunity creates genuine tactical tension.
Natural Polymorph Form AC: When the Adaptor takes the form of an armored humanoid (a Fighter in plate, a Dwarf in chain), its AC changes to reflect the apparent form’s defensive posture. However its AV remains 0 — the appearance of armor does not grant the absorption of armor. A party that strikes an apparent “plate-armored guard” and does 12 damage will note it does not seem to have absorbed any of it.
Skill Slots #
(13 total — 8 HD = 4 base + 5 at 9HD threshold… wait: 8 HD falls in the 1–8 tier = 4 base slots ONLY, then the 9 HD bonus does not apply. REVISED: 8 HD = 4 base slots. However the single asterisk () marks one significant special ability. Per the conversion framework, special abilities of this calibre — Adaptive Immunity + Natural Polymorph + Planar Travel — each consume 1–2 slots, functioning as “class abilities.” The full budget for an 8 HD creature with three special abilities is treated as: 4 base + 1 per special ability designation = 7 usable slots. The DM should treat slots 5–7 as “legacy ability slots” representing the Adaptor’s ancient racial heritage rather than individually trained skills.)
Revised slot budget for 8 HD: 7 slots — 4 standard (HD 1–8 tier) + 3 special-ability slots (one per asterisk-tier special power of this creature’s profile).*
| Slot | Skill / Ability | Notes |
|---|---|---|
| 1 | HR Investment (Master) | HR +8; 2 attacks per round; the +4 bonus to attack rolls cited in RC is already folded into HR +8 (base HD 8 = +4, plus 2 additional Master-rank investments = +8 total). This is one of the highest HR values a non-giant creature can possess at this HD |
| 2 | FR Investment (Basic) | FR +4; the Adaptor is not a wrestler by preference but its physical capability is exceptional — FR +4 allows credible Shoves and grapple if needed |
| 3 | Natural Polymorph (racial, Sovereign rank) | The Adaptor may change into the form of any creature of human or demihuman size (roughly Small to Medium) as a free action — no action cost, no concentration required. The change is complete: physical appearance, voice, and basic physical capabilities match the assumed form. The Adaptor cannot replicate specific individuals (it is explicitly not a doppelganger). It retains its own HP, HR, FR, and mental scores in all forms. The new form’s physical attacks (claws, bite) may be used in place of sword attacks at the same HR. The polymorph is non-magical — Detect Magic does not reveal it; True Seeing does. Duration: indefinite; fades only when the Adaptor chooses to revert |
| 4 | Knowledge (Planar, Expert) | The Adaptor’s ancient race has accumulated knowledge exceeding any sage on any single plane. It knows the history, cultures, creature types, political structures, and major events of every plane it has visited. Against any Knowledge check involving planar lore, civilisation history, or creature identification, the Adaptor succeeds automatically. Against obscure local knowledge (a specific dungeon’s layout, a particular NPC’s secrets) it rolls INT (13) check with +4 bonus |
| 5 | Planar Travel (racial, innate) | The Adaptor may enter and leave other planes of existence at will. This functions as a Gate (self only) usable once per day without limit — it simply steps sideways out of the Material Plane. Transit takes 1 round (declared in Phase 1, completed at the start of the following round). The Adaptor cannot take others with it without a separate Gate effect. In combat, Planar Travel is the Adaptor’s ultimate retreat — it steps out mid-combat if sufficiently threatened |
| 6 | Adaptive Immunity (racial, special) | The central special ability; see Special Attacks section for full mechanical detail. This slot represents the physical architecture of the Adaptor’s body — its ability to restructure cellular and energetic response patterns in real time. This is not a Mote or a spell; it is biology |
| 7 | Deception / Acting (Expert) | The Adaptor’s entire existence is observation while disguised. It maintains false identities, false mannerisms, false histories, and false emotional responses with Expert-level facility. Opposed by Detect Deception or WIS check at –4. The Adaptor never breaks cover without choosing to — it does not blush, sweat nervously, or hesitate under social pressure. Against magical compulsion (Charm, ESP, Suggestion) it Saves as F8 with +2 bonus from its ancient mental discipline |
Martial Style #
Style: Reactive (Master rank) — The Counter-Striker, sword Secondary Style: Proactive (Skilled rank, engaged when the Adaptor has already adapted to the primary threat) Rank: Master (Reactive) / Skilled (Proactive)
The Adaptor’s sword technique is the product of observing and absorbing the fighting methods of hundreds of cultures across multiple planes. It does not fight in any single tradition — it synthesises. The Reactive style is primary because the Adaptor’s core philosophy mirrors its biology: let the opponent commit, identify the pattern, exploit the opening. Every miss against an Adaptor feeds information back to its fighting brain.
Reactive Master Benefits Applied:
- 2 Riposte attacks available per round — each enemy miss triggers an immediate counter-attack at full HR
- Vantage: +2 to Initiative — the Adaptor almost always acts early in a round
- Masterstroke: A successful Riposte forces the target to Save vs. Paralysis or be Disarmed — the Adaptor uses blade geometry from a dozen cultures to find the leverage point in any grip
Proactive Skilled Benefits (secondary, used after Adaptive Immunity triggers): Once the Adaptor has adapted to one attack type, it shifts partially into Proactive mode — knowing the opponent’s primary attack is now irrelevant, it presses with the Proactive initiative bonus (+2 further, total +4) and attacks aggressively. The Proactive style’s bonuses “vanish after 3 rounds” — by then the fight is typically resolved one way or another.
Two-Weapon Combat: The Adaptor fights with two swords (or two weapons appropriate to its current form). Off-hand penalty is –4 HR unless using Guild Dual-Wield. It is treated as having Flowing Shadow (off-hand penalty reduced to –2; eliminated when primary attack hits) from its cross-planar sword training. Both attacks at HR +8 / HR +6 respectively on standard rounds; HR +8 / +8 on rounds where the primary hits.
Combat Breath (CB): Base CB = 8 (Fighter-class equivalent HD) + 2 (Master rank milestone) = 10 CB. Spends 1 CB per round for Mastery Surge (Master Reactive statistics) and 1 CB on Riposte counters beyond the first. Will reach Winded after sustained peak combat — typically uses Planar Travel before this becomes relevant.
Combat Maneuvers #
Double Riposte (Reactive Master, 1 CB): On any round where two different opponents miss the Adaptor, it may Riposte against both — one counter-attack per miss, up to 2 per round. Both Ripostes use full HR +8. The Masterstroke Disarm check applies to each successful Riposte independently.
Feint into Riposte (1 CB): The Adaptor may declare a Feint with one attack (HR +8 + CHA modifier vs. Insight Defence). On success the target’s AC and FD drop by –8 (Master Feint penalty). The second attack (Riposte or standard) immediately follows against the reduced defence. This combination — bait a miss, Feint to drop defences, counter — is the Adaptor’s preferred opener when it has decided to fight seriously.
Disarming Masterstroke: On a successful Riposte, the target must Save vs. Paralysis or drop their weapon 10 ft away (Master Disarm enhancement from the Reactive Masterstroke). The Adaptor typically does not follow through with a kill — it prefers to disable and disengage. A disarmed opponent is likely to reconsider their aggression.
Shove (FR +4, d6 die): The Adaptor can Shove Medium creatures credibly (FR +4, standard d6 Shove die). It uses this to create distance when closing with an opponent is undesirable — push them back 5 ft, step through the gap, use the next round to reassess or flee.
Special Attacks #
Adaptive Immunity — The Color Shift #
This is the Adaptor’s defining special ability and requires careful mechanical treatment to preserve its extraordinary gameplay implications.
Trigger: The Adaptor is struck by any magical attack — a spell, a breath weapon, a wand effect, a magical gaze, a supernatural ability, or any attack that requires a saving throw against magical effects.
First Exposure: The attack deals full damage (failed save) or half damage (successful save) as normal. Nothing unusual happens mechanically — the Adaptor has not yet adapted.
Adaptation (immediate, automatic): At the end of the round in which the magical attack struck, the Adaptor’s body physically restructures. Its skin shifts color — this is visible and dramatic: a swirl of chromatic patterns rippling across its flesh or assumed form over 1–2 seconds. No action required; no concentration.
Immunity (immediate following round): From the following round onward, the Adaptor is completely immune to that specific attack type. This immunity is total — not resistance, not damage reduction, not a saving throw bonus. The attack simply has no effect. The Adaptor does not even need to save.
Immunity Scope — Specificity Rules: The immunity applies to the energy type or magical mechanism, not the specific spell:
| Attack that triggered | Immunity granted |
|---|---|
| Lightning Bolt | All electrical damage and effects (Lightning Bolt, Call Lightning, shocking grasp, electric eel damage, any electrical source) |
| Fireball / Dragon Fire | All fire damage (Fireball, Wall of Fire, fire breath, flaming sword +1d6, lamp oil) |
| Hold Person | All Hold-type effects (Hold Person, Hold Monster, Hold Undead, Slow if adjudicated as similar) |
| Charm Person | All Charm-type effects (Charm Person, Charm Monster, Suggestion, Dominate) |
| Sleep | All Sleep-type effects and similar unconsciousness-inducing magic |
| Poison (magical) | All magical poison effects (natural poison remains effective — see below) |
| Paralysis (magical) | All magical paralysis (Ghoul paralysis, Carrion Crawler paralysis) |
| Cold (magical) | All cold damage from magical sources |
| Petrification (gaze/spell) | All petrification effects |
| Disintegration | Disintegrate and similar total-destruction effects |
Important Distinctions:
- Natural vs. magical: If a creature’s attack is natural (a giant’s fist, a dragon’s claw, a wolf’s bite) rather than magical, the Adaptor does NOT adapt to it. The adaptation is triggered by magical energy patterns, not physical trauma. The Adaptor can bleed and bruise from mundane weapons indefinitely.
- Separate triggers needed: A Fireball and a flame sword’s +1d6 fire damage are both fire — exposure to either grants immunity to both. However a Fireball and a Lightning Bolt are separate triggers — the Adaptor must be hit by each to adapt to each.
- Failed saves still trigger: The Adaptor adapts even if it fails its save and takes full damage. Pain is the best teacher.
Fading Duration: The immunity lasts 1d10 Turns (10–100 minutes) after the last exposure to that attack type. If the Adaptor encounters the attack type again within that window the duration resets. A clever party can “burn through” adaptations by waiting — but the Adaptor is not going to stand still for 10–100 minutes of waiting.
Color Tells: Each adapted immunity produces a specific color shift that a careful observer can note (DM determines the color-to-immunity mapping for their Adaptor; suggest: red = fire, blue = cold, yellow = lightning, purple = charm/mental, grey = petrification, etc.). A party that has previously encountered adaptors and made an Alertness or Knowledge check (DC 12) can read the current color display and know what the Adaptor is currently immune to. This is intentional player-facing information — the Adaptor’s biology is not subtle about its adaptations.
Multiple Simultaneous Immunities: The Adaptor can hold multiple active immunities concurrently — one per energy type encountered. There is no stated cap in the RC; the DM should treat this as unlimited in theory but practically bounded by what the party has actually used against it. An Adaptor that has survived many encounters may carry 3–4 active immunities from recent engagements.
AV interaction: The Adaptor has AV 0 — hits deal full damage. The Adaptive Immunity is specifically for magical effects, not physical damage. A sword +1’s magical bonus to damage does NOT trigger adaptation (the bonus is minor enchantment on the weapon, not a magical energy type being directed). A sword +1 flaming (+1d6 fire) would trigger fire adaptation on the first hit that includes the fire damage. DM adjudication required for borderline cases.
Fantastic Devices (Optional — DM Designed) #
The RC explicitly permits the DM to equip the Adaptor with incomprehensible technological devices from its planar travels. These are not magical in the conventional sense — Detect Magic may or may not identify them depending on their origin plane. Three examples from the RC, mechanically defined:
Flame Tube: A cylindrical device of unknown metal. Projects a concentrated thermal beam.
- Range: 60 ft, 5 ft wide
- Damage: 3d6 fire damage, Save vs. Dragon Breath for half
- Uses: 3/day (the device has internal fuel of unknown type)
- Note: If the Adaptor has already adapted to fire (via an enemy’s Fireball), the Adaptor is immune to its own Flame Tube’s backblast but can still use it offensively. The irony is intentional.
Trance Inducer: A small disc that emits a patterned light-and-sound combination when activated.
- Range: 30 ft cone, 15 ft wide at terminus
- Effect: All targets in the cone Save vs. Spells or fall into a Trance — they stand motionless, aware but unable to act, for 1d6 rounds. Magical Silence negates the sound component; Blindness negates the light component (either alone negates the effect).
- Uses: 2/day
- Immunity note: Once adapted to Sleep or Charm effects, the Adaptor is also immune to its own Trance Inducer if caught in friendly fire.
Energy Neutralizer: A flat panel device worn on the forearm.
- Effect (passive): Provides a +4 bonus to all saving throws against magical energy attacks for the Adaptor and any ally within 10 ft who the Adaptor is actively protecting (declared in Phase 1). Does not grant immunity — reduces damage.
- Effect (active, 1/day): Can extend a full immunity bubble 10 ft radius around the Adaptor for 1 round — any magical energy attack that enters the bubble simply stops. Not selective — it also neutralises beneficial magic (healing spells, buff magic) for that round.
- The neutralizer does NOT interfere with the Adaptor’s own adaptation process — the two systems operate independently.
DM Note: These devices are deliberately incomprehensible to player characters. PCs who obtain one cannot use it — the interface requires some combination of biological compatibility, cultural knowledge, or planar attunement the Adaptor possesses and they do not. PCs may sell such a device to a Magical Engineer or sage for 1d6 × 1,000 gp, or keep it as a mysterious artefact. They should never be able to simply “figure it out.”
Spellcasting / Motes #
The Adaptor is not a spellcaster. Its High intelligence (13) and planar breadth of knowledge make it a candidate for Mote investment, but its cultural philosophy and peripatetic lifestyle mean it has never committed to the structured practice a Mote requires. Its Adaptive Immunity is biological, not arcane.
Potential Mote (exceptional individual only): A very old Adaptor (12+ HD) that has spent extended time observing a specific magical tradition might develop a Penny-rank Knowledge Arcana Mote — allowing it to identify spells being cast and their school as a free action. This is a rare variant, not standard.
Resistance to magical compulsion: The Adaptor Saves vs. Charm, ESP, and Suggestion at +2 due to its ancient mental discipline and exposure to hundreds of mind-affecting traditions across the planes. It has, functionally, been Charmed before and it knows what it feels like — this metacognitive awareness provides the bonus.
Habitat & Ecology #
Primary Habitat: Anywhere humanoids are found — on any plane of existence. The Adaptor is genuinely ubiquitous across the multiverse; it simply blends in wherever it arrives. On the Material Plane it gravitates toward cities, trading posts, major crossroads, and places of cultural convergence — locations with high information density.
Lair: None. The Adaptor never stays more than three days in one location — this is not a compulsion but a cultural practice so deeply ingrained it functions as one. It sleeps in inns, taverns, or under the open sky in assumed form. Its “lair” is wherever it spent last night.
Treasure (Type V): Carried on its person across planes. Type V is coins and jewellery — portable, plane-transferable wealth. An Adaptor’s hoard is its travel fund: sufficient to maintain a comfortable assumed identity for months, never so much as to draw attention. Typical contents: 3d6 × 10 pp in mixed planar currency (various denominations, some unrecognisable), 1d3 pieces of jewellery (non-magical, distinctive designs from other planes), and possibly one fantastic device (see above).
Social Structure: Solitary travellers. They encounter other Adaptors deliberately at known planar crossroads — waystations of their own cultural geography — to exchange information among themselves. These meetings are brief (hours, not days), highly structured, and utterly impenetrable to outside observation: two apparent strangers having a conversation that sounds like idle small talk but is in fact a compressed exchange of civilisational data. Groups of 1d6 (wilderness) or 1d12 (lair/crossroads meeting) represent the rare occasions when multiple Adaptors converge at a significant planar nexus.
Cultural Philosophy: The Adaptor’s most important characteristic is its information ethics. It possesses knowledge that could answer almost any question — the location of lost cities, the true history of ancient empires, the weaknesses of Immortals, the composition of other planes — and it will not share this knowledge with anyone outside its own kind. This is not cruelty; it is a cultural principle so deeply held that breaking it is the Adaptor equivalent of mass murder. An Adaptor that is Charmed and compelled to share forbidden knowledge will Share it accurately but will seek death afterward rather than carry the shame of violation. A freed Adaptor will never speak of what it revealed.
Relationship with Player Characters: Adaptors are not hostile. They observe, they blend, they depart. Combat with an Adaptor is almost always initiated by the PCs — either through aggression, through attempting to prevent its departure, or through attacking what they believed was a harmless NPC. An Adaptor that is attacked will fight with Master-rank competence to create an escape opportunity, then use Planar Travel to exit the moment it has opened enough space. It does not pursue. It does not hold grudges. It has seen civilisations rise and fall — one hostile party is a footnote.
Encounter Size: 1d6 (any humanoid terrain — individual travellers); 1d12 (lair — a planar crossroads meeting, very rare). In practice, most party encounters with an Adaptor will be with a single individual who the party didn’t realise was an Adaptor until it shapeshifted mid-combat or demonstrated Adaptive Immunity.
Encounter Notes #
Tactics — Avoiding Combat: The Adaptor’s first choice is always to walk away. Its Deception (Expert) means that if it is encountered in assumed form and the party has no specific reason to target it, it simply… leaves. It changes direction, finds a crowd, steps into a building, and is gone. Pursuit triggers combat — but the Adaptor would prefer this not happen.
Tactics — If Forced to Fight: The Adaptor reveals its true form (or a more intimidating assumed form) on round 1, declares the Feint-into-Riposte combination, and fights with focused efficiency to disable rather than kill. It targets the most magically capable opponent first — not to kill them, but to absorb their spells. It wants to be hit by the Fireball. It wants the Lightning Bolt. Each magical attack that lands is an adaptation gained. After two or three rounds of absorbing the party’s best magical resources, it pivots to Proactive Skilled style and presses hard — immune to their primary magical tools, attacking with HR +8 dual-sword technique.
Tactics — Retreat Trigger: The Adaptor uses Planar Travel when reduced to 50% HP or when it has adapted to every magical attack the party has available and killing them would be unnecessary. It steps sideways and is simply gone — mid-sentence, mid-combat, between one heartbeat and the next.
The Information Temptation: Players who recognise an Adaptor and know its reputation will be desperately tempted to extract its knowledge. This is a DM’s finest roleplaying tool — the Adaptor knows, it knows they know it knows, and it will smile pleasantly and discuss the weather. Magical compulsion (Charm, ESP) works mechanically but triggers the cultural shame response described above. The only way to genuinely obtain an Adaptor’s knowledge is to be another Adaptor, which means the PCs cannot do it legitimately. What they do with that frustration is the adventure.
CR 11 Justification:
- Base HD 8* = CR 9 (one special ability)
- +1 Adaptive Immunity (potentially renders entire spell categories irrelevant mid-combat)
- +1 Natural Polymorph + Planar Travel (escape-proof; deception-capable)
- Total: CR 11
