The Great Brass Mangle

A 20 foot section of flooring consisting of overlapping, circular brass plates that serve as the tops of massive subterranean gears. When triggered, these plates spin in opposing directions, creating a meat-grinder effect for anyone standing on them.

Hazard EntryMechanicalLevel4Simple

The Great Brass Mangle

4LevelUncommonRarityDungeonEnvironment
ClockworkTrapPhysical
Level4
|
HP60
|
AC16
|
TypeMechanical
|
ComplexitySimple
|
RarityUncommon

Defenses

AC16
Hard10
HP60
BT 30
Fort++4 (Constitution)
Ref+-2 (Dexterity)
Will+Immune
Immune
Poison, Psychic, Necrotic, Poison, Conditioned
Resist
Piercing, Slashing
Weak
Cold damage (freezes lubricant, disadvantage on reset rolls)
ClockworkTrapPhysical

Detection

PerDC 15
StlDC 15
InitNone

The floor is made of polished, interlocking brass discs etched with geometric patterns. The air smells of heavy machine oil and ozone, and a faint, rhythmic clicking sound emanates from the walls.

Standard Engagement

Trigger

Pressure Plate: The trap triggers when a creature weighing 50 pounds or more steps onto the third floor disc in the sequence.

Routine

Once triggered, the gears rotate violently for 1 round before locking back into place.

Reset

The mechanism automatically resets after 1 minute of inactivity as the internal springs rewound.

Whirling Mangle

When triggered, the plates spin. Every creature standing on the 20 foot floor section must make a DC 15 Dexterity saving throw. On a failure, a creature takes 22 (4d10) bludgeoning damage and is knocked prone. On a success, the creature takes half damage and remains standing.

Difficult Terrain

The rotating and oil-slicked floor plates count as difficult terrain even when the trap is not active.

Grinding Inertia

If a creature is prone on the floor when it triggers, they have disadvantage on the Dexterity saving throw.

Description

A 20 foot section of flooring consisting of overlapping, circular brass plates that serve as the tops of massive subterranean gears. When triggered, these plates spin in opposing directions, creating a meat-grinder effect for anyone standing on them.

Discovery

A DC 15 Intelligence (Investigation) check reveals that the floor plates are not fixed and show signs of heavy friction on their edges. A DC 15 Wisdom (Perception) check notices small droplets of oil and metallic shavings caught in the cracks of the floor.

Archival Lore

Created by the gear-mage Krazzt to protect his inner sanctum, this floor was designed to utilize the kinetic energy of the dungeon's central steam core to eliminate intruders without the need for sentries.

Environment
Dungeon
Theme
Clockwork
Creator
Krazzt the Gear-Mage
Purpose
A high-security corridor trap designed to catch and crush intruders before they reach the main vault.
Game System
D&D 5E
Art Style
Highly detailed isometric ink drawing with golden-yellow color washes and technical annotations.
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