Yesterday, Twitter user arb8020 posted this:

It went semi-viral within AI Twitter and users began experimenting with "goblin mode" and hypothesizing about the source of the bizarre behavior. LM Arena provided evidence for the phenomenon from their traffic:

"It's true. Here's a plot of GPT models and their usage of 'goblin', 'gremlin', 'troll', etc over time. There's no anti-gremlin system instruction on our side, we get to see GPT-5.5 run free." — arena

Some hypotheses about what causes this:

"My boring hypothesis is that AIs that are trying overly hard to write well without really understanding good writing get overly fixated on one or two tricks… Goblins are an evocative metaphor and there is a certain microstyle that emphasizes goblin-like imagery. I think a couple of the RLHF raters must have been really into it and some quirk of the training process overemphasized their positive feedback." — slatestarcodex
"I kind of hope the human labelers just love goblins and the model learned to goblin maximize." — AmandaAskell
"my completely random hypothesis on the goblin thing is it's a safe way for the model to reason about reward hacking tendencies" — qorprate
"my best guess about goblin mode is [...]

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Outline:

(02:58) A closer look

(03:29) Creature that starts with G

(04:33) Favorite word that fits g___n

(06:05) Fantasy conversation

(06:34) Goblin valence

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First published:
April 29th, 2026

Source:
https://www.lesswrong.com/posts/BvnmHdCghr5y3q4nA/goblin-mode-24-hours-later

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Narrated by TYPE III AUDIO.