These rooms are covered in runes from floor to ceiling. One of them (d6 for which) contains a strange crystalline implement (an Ispenil), which is hovering in midair, and will point to the first non-goblinoid to enter. If all of those entering are part goblinoid (For example, Half-Orcs) there is a 50% chance it will point to any of them. If not, it cannot be removed, but will do no harm to them. If a goblinoid attempts to remove it they must save vs. spells or attack the nearest creature.
It can be used to create runes with various effects. However, if it is used on a goblinoid or part-goblinoid, they must save vs. spells, or lose 1d6 HP. If used on them again, they will begin to attack all creatures around them other than the one who used the Ispenil on them, who can give them simple commands (Including "stop attacking", or "Follow his/her orders"). They will not eat, sleep, or drink, unless ordered to. They will fight until dead or ordered to stop.