Crystal Cave terrain

Originium veins run raw and glittering through the stone here, and the ruins of an older civilization show in cracked walls and half-buried machinery. The party is traversing this deepest recorded layer of the Underdark.

The location’s inhabitants

Old guardians, remnants of the civilization that came before, and things drawn to the raw Originium dwell here. Entering their territory uninvited may provoke them to attack, otherwise they’ll flee or investigate players that seem non-threatening.

  • Common: Earth Elementals (resting in the old ruins), Gray Ooze, Deactivated Warforged Prototypes (remnants of the old civilization), Mimics
  • Uncommon: Dragon Swans (near Sarcophagus facilities), Xorn
  • Dangerous: Umber Hulk, Beholder Zombie

The Location’s possible encounters

The crystal caves are often traversable, though raw Originium deposits and unstable ruins can slow the party down — and pose a hazard beyond the creatures here.

Roll a 1d4 to determine which encounter that follows:

  • 1 - E1
  • 2 - E2
  • 3 - E3
  • 4 - E4

E1. Difficult Terrain

Difficult terrain hinders the party, one may traverse it by overcoming a skill check. Simply going around is also an option by spending more time.

ObstacleSkill check
Unstable ruin debrisDC 12 Strength Check
Raw Originium exposureDC 12 Constitution Check
Crystalline outcropsDC 10 Dexterity Check

E2. Common Encounter

Old guardians and remnants of the civilization before inhabit this stretch of crystal cave.

Roll a 1d4 to determine the creature encountered and a 1d4 to determine what the creatures are currently doing:

  • 1 - on alert
  • 2 - wandering
  • 3 - working
  • 4 - resting
Common CreatureNumber of creatures
1. Earth Elemental (in old ruins)1d2 (1–2)
2. Gray Ooze1d2 (1–2)
3. Deactivated Warforged Prototype1d4 (1–4)
4. Mimic1d2 (1–2)

E3. Uncommon Encounter

Rare and singular beings, some ancient relics and some drawn by the raw Originium in the stone.

Roll a 1d2 to determine the creature encountered and a 1d4 to determine what the creatures are currently doing:

  • 1 - on alert
  • 2 - wandering
  • 3 - working
  • 4 - resting
Uncommon creatureNumber of creatures
1. Dragon Swan1
2. Xorn1

E4. Dangerous Encounter

These creatures rule the deepest crystal caverns, guarding the old ruins and the raw Originium within.

Roll a 1d2 to determine the creature encountered and a 1d4 to determine what the creatures are currently doing:

  • 1 - on alert
  • 2 - wandering
  • 3 - working
  • 4 - resting
Dangerous creatureNumber of Creatures
1. Umber Hulk1
2. Beholder Zombie1

Aftermath

The party may loot the creature’s belongings if they have any. Parts of the creatures may be claimed as a trophy or collected as material for artisans. Warforged prototype components and raw Originium samples may be of particular value to Rhine Labs, Chrysalis Labs, or the Dwarves Union.

After overcoming the encounter the party may continue on deciding their next move.