You have to kill it with fire or acid. Everything else just delays it. You hit it for 15 damage. In three rounds it will start healing that damage at 3 HP per round. If you let it go, it comes back whole. Severed limbs crawl back. The head keeps biting. Kill it with fire.
What a Troll Is #
A troll is an 8 ft thin humanoid with ferocious features, sharp teeth, and mottled rubber-like skin. It is a carnivore that prefers human and humanlike victims. It lives nearly anywhere, often in the ruined dwellings of its victims.
The defining property: Regeneration. Not just HP recovery — the troll regenerates severed limbs and can fight as scattered pieces. Only fire and acid prevent regeneration.
Regional distinction. Trolls are found across the Known World in greater variety than their common form suggests. Regional populations have adapted to specific climates and territories, producing distinct variants in coloring, build, and behavior. What does not vary: the regeneration, the appetite, and the need for fire or acid to permanently kill any of them.
Core Statistics — Common Troll #
| Stat | Value |
|---|---|
| Hit Dice | 6d8+3* (avg 30 HP) |
| AC | 16 |
| AV | 2 |
| HR | +7 |
| FR | +7 |
| FD | 17 |
| Move | 120 ft (40 ft encounter) |
| Attacks | 2 claws (1d6/1d6) + 1 bite (1d10) |
| No. Appearing | 1d8 (1d8) |
| Save As | Fighter 6 |
| Morale | 10 (8 vs. fire/acid) |
| Treasure | Type D |
| Alignment | Chaotic |
| Intelligence | Low (INT 6) |
| XP | 650 |
| Terrain | Cavern, Wilderness |
RC original AC 4 (descending) = Ascending AC 16.
Skill Slots (4 total — 6+3* HD = 4 base + 1 asterisk; Low INT 6) #
| Slot | Skill | Notes |
|---|---|---|
| 1 | HR Investment (Skilled) | HR +7 |
| 2 | FR Investment (Basic) | FR +7 |
| 3 | Regeneration Suite (innate, special) | 3 HP/round from round 3 after damage; severed limbs rejoin; pieces fight independently; fire/acid prevents regeneration. The asterisk. |
| 4 | Persistent Threat (innate) | Unless totally destroyed by fire or acid, eventually regenerates completely; head and claws fight at 1+ HP |
Regeneration — Complete Mechanics #
Timing #
Regeneration begins 3 rounds after damage is dealt.
- Round 1: Troll takes damage
- Rounds 2–3: No regeneration (wound is fresh)
- Round 4+: Regeneration begins at 3 HP per round
The 3-round window: The party has 3 rounds of dealing damage before regeneration starts undoing it. Against a troll at 30 avg HP, the party must deal 30 HP net before round 4 or the troll begins recovering faster than it takes damage.
Severed Limbs #
A severed troll arm crawls toward the troll’s body and reattaches. If the body is not accessible (destroyed, across a fire barrier), the limb cannot rejoin — but it continues fighting independently.
Fighting in Pieces #
The head and claws of the troll continue to fight as long as the creature has 1 hit point or more. A party that chops the troll into pieces has not solved the problem — they have created multiple independent threats still fighting for the troll.
Fire and Acid #
The troll cannot regenerate damage from fire or acid. Morale drops to 8 when facing fire or acid attacks.
Killing a troll: Reduce it to 0 HP with fire or acid, OR reduce it to 0 HP with any weapons AND apply fire/acid before it regenerates back above 0.
The common mistake: Party deals 30 damage, troll hits 0 HP and falls. Party moves on. Three rounds later, troll begins regenerating. In 10 rounds it is at 30 HP again. In 30 rounds it is fully healed, standing, and following the party.
Unless totally destroyed by fire or acid, a troll will eventually regenerate completely.
Morale — The Two States #
Normal (Morale 10): Confident, aggressive, fights through damage because it knows it regenerates. Does not retreat from standard weapon damage.
Vs. Fire/Acid (Morale 8): The troll knows fire and acid are existential threats. It recognizes the danger and may retreat from sustained fire attack. The troll fears fire in a way it does not fear swords.
Regional Variants #
Three established troll populations are documented across the Known World, each adapted to a distinct environment. The regeneration mechanics, fire/acid vulnerability, and severed-limb fighting rules apply to all three variants without exception.
Common Troll (Monstrum Imbecilus Rex) #
Territory: Wilderness hills, caves, and ruined structures throughout the Known World — the standard troll encountered in most regions.
Appearance: Not noted for intelligence. Tall, light green with dark green spots (or vice versa). Black, straw-like hair on top of the head in a straw-like shape. Seen with studded red leather belt and sashes; spiked whips. Long, slimy, carrot-shaped nose. Inhabits wilderness hills and the gloomiest forests.
Statistics: As Common Troll above, unmodified. This is the reference population.
Mountain Troll (Monstrum Erroneus Hyborianus) #
Territory: Hyboria, polar regions, and glaciers high in the mountains — the most cold-adapted troll population.
Appearance: Not very bright either. Tall and hunched forward; dull white or grey, with light green shades. Thick, wooly hair on head, shoulders, back, and forearms. Polar bear hide around waist and laced on feet; large bone as weapon. Common in Hyboria, polar regions, and glaciers high in the mountains.
Behavioral note: The Mountain Troll operates in the harshest cold environments in the Known World. Its wooly coat provides natural cold protection, and its large-bone weapon (adapted for breaking through ice and permafrost as much as for combat) makes it a more dangerous physical opponent than the common troll. The cold environment means fire-based solutions are harder to execute reliably — wind, moisture, and cold work against open flames at high altitude or in polar terrain.
Statistics: As Common Troll, with the following changes:
| Stat | Value | Change from Common |
|---|---|---|
| Hit Dice | 6d8+5* (avg 32 HP) | +2 HP (cold-hardened constitution) |
| AC | 17 | +1 (wooly coat + polar bear hide adds natural insulation that deflects blows) |
| AV | 3 | +1 (denser tissue from cold adaptation) |
| Attacks | 2 claws (1d6/1d6) + 1 bone weapon (1d10+2) | Bone weapon replaces bite as primary heavy attack; +2 from exceptional size |
| XP | 750 | +100 |
Fire note: In mountain/polar terrain, fire-based solutions suffer a –1 to effective damage from environmental conditions (wind, moisture, cold). Acid remains fully effective.
Swamp Troll (Monstrum Carnivorus Maximus) #
Territory: All Known World wilderness, especially humid caverns, steamy swamps, and Trollhattan (Broken Lands) — the most widespread and most dangerous regional troll population.
Appearance: No wits but great appetite. Tall, grey-green with swampy-brown splotches. Oozing warts and bumps. Large, drooling mouth with protruding fangs. Long purple or black hair, tied in the back. Older specimens with muddy-grey or white hair. Few spiked armor pieces, full-faced helms, and barbed-wire hunting nets. Common in all Known World wilderness, especially humid caverns, steamy swamps, and Trollhattan.
Behavioral note: The Monstrum Carnivorus Maximus is named with accuracy — it is the most predatorily focused troll population, with a wider range of hunting tools (barbed-wire nets, spiked armor pieces) that suggest a population that has spent generations refining its approach to catching prey rather than simply ambushing it. The barbed-wire nets are particularly dangerous: a target caught in one that is also taking troll claw damage in the same round cannot easily escape.
Statistics: As Common Troll, with the following changes:
| Stat | Value | Change from Common |
|---|---|---|
| Hit Dice | 6d8+4* (avg 31 HP) | +1 HP |
| AC | 17 | +1 (spiked armor pieces, full-faced helm) |
| AV | 3 | +1 (armor provides meaningful absorption) |
| XP | 700 | +50 |
Additional skill — Slot 4 modified: Net Hunting (Basic) — carries 1d3 barbed-wire nets (range 15 ft; target Save vs. FD 15 or entangled; entangled targets take 1d4 barbed damage per round of movement; –2 to all attacks while entangled). The Swamp Troll uses nets in the opening round of combat to restrain prey before closing to claw/bite.
Regional Variant Summary Table #
| Variant | HD | AC | AV | Move | Key Trait | XP |
|---|---|---|---|---|---|---|
| Common (Imbecilus Rex) | 6d8+3* | 16 | 2 | 120 ft | Standard regeneration | 650 |
| Mountain (Hyborianus) | 6d8+5* | 17 | 3 | 120 ft | Cold-hardened; bone weapon; fire less effective | 750 |
| Swamp (Carnivorus Maximus) | 6d8+4* | 17 | 3 | 120 ft | Barbed-wire nets; armored; widest range | 700 |
Encounter Notes #
The dismemberment mistake: The party’s fighters hack the troll apart — both arms severed, then the body brought to 0 HP. They move on to the next room. None of them thought to use fire. Three rounds later: the troll body begins healing. The arms crawl back and reattach. In 20 rounds the troll is at full HP and follows the party’s scent.
The fire solution: The Cleric knows about trolls. When the troll falls to 0 HP, they immediately pour burning oil on the body parts and apply a torch. The troll is destroyed. Each severed arm is also burned. This takes 1–2 rounds of careful work during which the party is vulnerable.
The fire retreat: The party uses fire against the troll. Morale check at 8 — the troll may retreat. A retreating troll is not dead. It will return when its wounds heal, possibly with reinforcements from the 1d8 lair.
CR justification:
| Rank | CR | Notes |
|---|---|---|
| Common Troll | 7 | 6+3* HD; regeneration requires fire/acid; severed pieces fight |
| Mountain Troll | 8 | +2 HP, +1 AC, +1 AV; fire less reliable |
| Swamp Troll | 8 | +1 HP, +1 AC, +1 AV; net hunting adds first-round restraint |
