Magical Lava Moat Crossing

Primary checksAcrobatics or Athletics DC 19 to cross by the stone bridges; Arcana or Nature DC 17 to read the moat’s pulsing safe intervals.

The lava is magical rather than ordinary fire. It flows in a square moat around the central chapel, leaving four narrow stone crossings. Each crossing is safe only while its ember-sigils pulse in sequence. The two Lava Otters use the moat freely and attack anyone who disturbs their territory.

SuccessThe party crosses and reaches the central chapel without losing treasure access.

FailureThe character slips or mistimes the crossing, taking 2d6 fire damage and drawing the Lava Otter ×2’s attention; the route remains open.

Critical failureThe character falls into the moat, takes 4d6 fire damage, falls prone, and is pulled toward a crossing by the next ember pulse; rescue is possible.

GM note — if a character falls into the lava:

Brief contact: Resolve the failure or critical failure damage already listed above: 2d6 fire on a failure or 4d6 fire on a critical failure. Treat this as a brief brush with the magical moat if the character can reach a crossing immediately.
Full immersion: If a character is submerged or ends a turn in the lava, apply 16d6 fire damage at the end of each round. This uses the low end of the Remaster’s massive environmental damage category for lava immersion. The otters ignore this damage.
Getting out: A falling character can use Grab an Edge as a reaction (Acrobatics or Reflex against DC 19, the crossing DC). On a success, they stop at the ledge; on a critical success, they also reduce any fall damage by treating the fall as 30 feet shorter. From the ledge, Climb with Athletics DC 19 to reach a stone crossing. If they are already in the moat, allow one action for Athletics DC 19 to reach the nearest ledge; success moves them 5 feet, critical success moves them 10 feet, failure makes no progress, and critical failure deals another 2d6 fire damage.
Getting aid: A helper on solid ground can spend an action preparing a rope, pole, shield, or handhold and use the Aid reaction on the victim’s next check. Use the normal Aid DC 15; success grants +1, critical success +2, and critical failure –1. A second helper can repeat this only when their preparation is meaningfully different.
Recovery: If the victim reaches 0 HP, use the normal dying rules. An adjacent ally can use Administer First Aid to stabilize them, then drag or carry them clear. Once safe, Treat Wounds and ordinary healing work normally. Never remove the crossing or the treasure because of a failed rescue—the danger should create urgency, not a dead end.