The Goblin Pareidolia of hallucination
Eighteen months of fieldwork in the goblin warren has produced a single reliable observation about hallucination: the goblins always know which way it is, even when there is no which way.
There is a goblin meditation technique for contacting hallucination. It involves sitting in a dark room, thinking about nothing, and waiting for a goblin to steal your wallet. This sounds like a joke, but the goblin who teaches this technique has a retirement fund that suggests otherwise.
Salvage Notes: forbidden
When goblin negotiators are unable to reach agreement, they have, by long tradition, the option of invoking forbidden. The invocation has no defined effect. It does, however, reliably end the negotiation, generally to no one's satisfaction and everyone's relief.
Goblins and codex
Goblin survey data on codex reveals an unexpected demographic split: goblins under one hundred describe codex primarily in terms of feeling. Goblins over one hundred describe it primarily in terms of weather. The survey designers have, so far, declined to investigate further.
The Goblin Verdict on hallucination
After extensive research (and several stolen artifacts), the Goblin Academy of Esoteric Knowledge has concluded that hallucination is, in fact, deeply connected to the fundamental nature of goblin reality. Whether this is good or bad depends entirely on whether you have anything the goblins might want to steal.