Echo Gems
Level 17 Lurker
XP 1600

Glittering crystals stab out from the room’s walls and attune to energy created in their presence. Dragons keep these gems to further beef up their breath weapons.

Trap: This trap consists of eight 2-by-2 clusters of echo gems placed throughout the room. Creatures adjacent to the gems gain vulnerability to certain damage types.Perception     No check is necessary to notice the echo gems.Dungeoneering     DC 25: The character identifies the echo gems’ function.Initiative +0TriggerWhenever a space containing an echo gems cluster is in the area of a close or area attack, that cluster becomes attuned to the attack’s damage type, if the attack has one. Each creature adjacent to that cluster gains vulnerable 10 to that damage type while adjacent to the cluster. Each time a cluster is in the area of a close or area attack that has a damage type, it becomes reattuned to the damage type of that attack.
The first time any of the trap’s clusters is triggered, the trap rolls initiative. Each time the trap’s initiative comes up, a random cluster that has been attuned makes an attack.
Attack • ZoneStandard Action      Close burst 2
Targets: Each creature in the burstAttack: +20 vs. ReflexHit: 2d8 + 7 damage of the type to which the cluster is attuned.Countermeasures     A character can attack the echo gems cluster (AC 31, other defenses 29; hp 80; vulnerable 10 thunder). If this attack hits the cluster and deals damage that has a type, the cluster becomes attuned to that damage type. Reducing the cluster to 0 hit points causes it to make the attack described above before it is destroyed, if the cluster was attuned.
     Arcana DC 20: A character can make a check as a standard action to cause a cluster within 5 squares of the character to lose its attunement.

Published in Draconomicon: Metallic Dragons, page(s) 60.