Trap 1 — The Copper Mire Revised: tree blights, needle blights, and the things that drop from above

Lower WoodsForest PathSetpiece Encounter

Look at the mud — it tastes of copper and old iron. — Verse 1
The oaks lean in to bar our way.
We were told the path was straight.
Our candles die in the damp air. — Verse 1

A 200-foot stretch of forest path that narrows into a rust-red bog at its center. Two of the trees lining the path are tree blights; twelve needle blights are hidden among the brush at the verges; and two black oozes cling to the canopy directly above the deepest mud, waiting to drop on anyone reckless enough to run beneath them. The whole encounter is choreographed: the blights drive the party forward into the muck, and the muck is where the oozes are waiting.

The Scene

The trail dips into a hollow where the trees crowd in close — trunks five feet apart on either side, branches knitting overhead into a low, sweating canopy. The center 40 ft of the path is a glossy copper-red mud, ankle-deep at its edges and waist-deep in the middle. The mud smells of blood and metal. A single skeletal hand juts up from the mire, fingers cupped as if begging.

Torches and candles brought into the hollow gutter in the damp; magical light still works but feels dim. The wind dies. The party will feel watched before they see anything.

DM only — the choreography

This is a funnel. The needle blights begin firing from the brush on both sides; the tree blights step into the path behind the party once they're committed; the oozes drop the moment a PC stands in waist-deep mud. The whole trap rewards the party who stops and thinks — and punishes the party who panics forward.

Spotting It

The Mud (The Mire Itself)

The center 40 ft of the trail is a copper-rich blood bog. Anyone who steps onto the mire makes a DC 14 Dexterity save. Fail = sunk to the waist, gaining the Grappled and Restrained conditions; sinks an additional 5 ft each round they do not escape. Fully submerged = holding breath.

Escape. A Restrained creature uses an Action and makes a DC 14 Strength (Athletics) check. An ally on solid ground using a rope or weapon haft (DC 12 Athletics) grants advantage on the next escape attempt.

The iron drinks faith

While submerged at least to the waist, a creature has disadvantage on spell attack rolls and on Concentration saves, and the spell save DC of any spell they cast is reduced by 2. The lyric: watching our faith dissolve like salt. The paladin, druids, and ranger should feel the dampening on a passive Insight 13 just before someone goes in.

The Encounter

Two Tree Blights (the walls that close)

Tree Blight · CR 7 (2024 MM) · AC 15 · HP ~136 · Speed 30 ft.
Multiattack: 2 Slams (+7 to hit, ~3d6+4 bludg each).
Vulnerable: fire. Resistant: bludgeoning, piercing.
Special: Animate Trees / False Appearance until it moves.

The two tree blights are flanking the path at roughly the two-thirds mark — that is, the party passes between them before they realize. They do nothing on round 1 (False Appearance). On round 2, once a PC reaches the mire's edge, they step into the path behind the party, closing the rear. From there they slam anyone within reach and act as living walls — the party cannot easily retreat the way they came.

Tactical note. They do not wade into the mire (no advantage to it; they want the party stuck, not themselves). They hold the line behind the party and let the needle blights and oozes do the killing.

Twelve Needle Blights (the drivers)

Needle Blight · CR 1/4 (2024 MM) · AC 12 · HP 11 · Speed 30 ft.
Claws +3 melee (2d4 piercing) OR Needles +3 ranged 30/60 ft. (2d6 piercing).
Stealth +3 in undergrowth.

Twelve needle blights are hidden in the brush — six on each side of the path, scattered along the 200-ft approach. Their job is to drive the party forward into the mud. On their initiative, they fire needles at the rearmost PCs only, and they back up 5 ft into denser brush each round so the party can't easily close on the firing line. If a PC charges into the brush after them, the nearest two close-in with claws and the rest keep shooting at the runners on the path.

Read aloud as they engage:

Read aloud Needles whistle out of the brush — fast, then faster, then a hiss of them, sleeting from both sides of the trail. Every one of them is aimed at your back. The path ahead is wet and red and waiting.

Two Black Oozes (the ambush above)

Black Pudding · CR 4 (2024 MM) · AC 7 · HP 85 · Speed 20 ft., climb 20 ft.
Pseudopod +5 (1d6+3 bludg + 4d8 acid; nonmagical metal armor takes a permanent −1 AC penalty until repaired).
Amorphous, Corrosive Form, Spider Climb. Split (when reduced to 10+ HP by slashing or lightning, it divides into two puddings of half max HP).
Damage immunities: acid, cold, lightning, slashing.

Two black oozes — slick, lightless black masses about the size of a hunched dwarf — are spider-clinging to the underside of a thick low branch directly above the deepest section of the mire. They are silent and easily missed (passive Perception 17). The moment any creature stands in waist-deep mud below them, they drop onto that creature (no attack roll — the drop is the surprise). The struck creature takes 4d8 acid damage from the impact, must make a DC 14 Strength save or fall prone, and is now sharing a 5-ft square with a black pudding that is itself partially in the mire. Initiative is rolled for the puddings immediately at the top of the next round.

Tactical note. The puddings are dangerous, but the table needs to know: the mire is what kills people, not the puddings. The puddings exist to make the mire impossible to stand still in. A pudding will engulf a Restrained PC and the player will need help from outside.

Running the Round Order

RoundWhat Happens
1 Party enters the hollow. Needle blights open fire from both verges, aiming at the rearmost PCs. Tree blights are False Appearance — silent. Lead PCs reach the edge of the mire (Perception 14 to see it for what it is).
2 Tree blights animate behind the party and slam the trailing PCs. Needle blights keep firing. Any PC standing in waist-deep mud is now in pudding-drop range.
3 Black oozes drop. Roll initiative for them. Restrained PCs in mud are now in real trouble.
4+ Adjust to the table. If the party is winning fast, the rear tree blight starts uprooting and walking forward into the trail (denying retreat). If the party is losing, needle blights run out of needles (each has ~3 volleys) and start to flee back into the brush.

Deflate / Smart Plays

DM only — when to ease off

This is a heavy encounter for a level 4–5 party of ten. The tree blights are the swing variable. If the table is grinding, have one tree blight reduced to half HP wrench its roots free and stagger away into the deeper wood (the blight is a tool of the Aunts and they recall it when one is wounded). The remaining setup is still a serious fight, but no longer an extinction event.

After the Fight — The Pilgrim in the Mud

The hand sticking out of the mire belongs to a long-dead pilgrim — a woman in a travel-stained cloak, drowned waist-deep and preserved by the cold iron in the water. The party has to dig her out to find what she was carrying.

Digging her out. One PC uses an Action and makes a DC 13 Strength (Athletics) check; success exposes the body fully. Two PCs working together auto-succeed and finish in one round. Without a proper exhumation, only her satchel and the items in her belt-pouch come free; the boots stay buried.

The Pilgrim's Loot