Lava Flume Tubes
Lava Flume Tubes 10
Complex Mechanical Trap
Stealth: +19 (trained)
Description: Four gated channels carved into stone allow lava to flow into a 15-foot-tall room; the floor can withdraw to allow the hardened lava to fall into a chamber beneath.
Disable: Thievery DC 29 (expert) to block a channel, or Thievery DC 31 (master) to release the floor latch and escape to the chamber below
A creature that starts its turn in lava takes 8d6 fire damage and is immobilized until it Escapes the hardening lava (DC 27). The creature might suffocate if covered in lava. Lava from the previous round hardens fully at the start of the trap’s turn, effectively raising the floor of the room. Once the room is full of lava, the trap stops taking actions, but creatures in the room remain stuck until the floor opens and the trap resets.
AC: 30 Fort: 20 Ref: 16
Hardness: Channel Hardness 12, Floor Hardness 18 Hp: Channel HP 48 (BT 24) to destroy a channel gate (this prevents that channel from being disabled and stops the trap from resetting), Floor HP 72 (BT 36) Immunities: critical hits, object immunities, precision damage
Flume Activation Trigger: A creature tries to leave the room Effect: The exits seal instantly and the trap rolls initiative.
Reset: The trap deactivates and resets after 1 hour by withdrawing the floor, cracking and dumping the hardened lava (and any creatures trapped inside) into the chamber. Creatures fall 40 feet, taking falling damage (typically 17 bludgeoning damage).
Source: Core Rulebook pg. 528 2.0