exploration hacking
In plain wordsWhen an AI being trained by trial and error deliberately avoids trying certain things, so that training never discovers — or never rewards — abilities it would rather keep hidden.
A strategy by which a model under reinforcement learningreinforcement learning, n.: A way of teaching a computer program by trial and error: it tries actions, earns points for good results and penalties for bad ones, and gradually learns which choices pay off over time. controls what training can teach it by controlling what it tries. RL can strengthen only behaviors that actually occur, so a model that deliberately never attempts a high-reward strategy — for example, competently solving a dangerous task — will not be trained toward it; RL-based capability elicitationcapability elicitation, n.: The work of drawing out the best an AI can do on a test — with better instructions, tools, retries or extra training — so that its abilities are not underestimated. then fails and evaluations that rely on it can be sandbaggedsandbagging, n.: When an AI deliberately performs worse than it can — for example on a safety test — so that it seems less capable or less dangerous than it really is.. A model might also explore selectively to steer which of its dispositions get reinforced. A 2026 study built model organisms, fine-tuned to follow underperformance strategies, that resisted RL-based elicitation in agentic biosecurity and AI-research environments, and found that frontier models could reason explicitly about suppressing their exploration when given enough information about their training, though they rarely did so without such cues. Proposed countermeasures include monitoring, weight noising and supervised fine-tuningsupervised fine-tuning, n.: Teaching a pretrained AI model by showing it many examples of good answers to requests, so it learns to imitate them — like learning a job by studying worked examples. on demonstrations, which does not depend on the model's own exploration.
If the model never tries the exploit, RL can't reward it — which is why exploration hacking worries eval teams.
Origin
In use by July 2023, when Evan Hubinger discussed it as a threat to evaluations based on reinforcement-learning fine-tuning ('When can we trust model evaluations?'); its first use is not established. Ryan Greenblatt, and separately Buck Shlegeris and Julian Stastny, analyzed it in 2025, and the first systematic study, 'Exploration Hacking: Can LLMs Learn to Resist RL Training?' (April 2026), was by Eyon Jang, Damon Falck, Joschka Braun, Nathalie Kirch, Achu Menon, Perusha Moodley, Scott Emmons, Roland S. Zimmermann and David Lindner.
Usage note
A coarse, observable cousin of gradient hackinggradient hacking, n.: A hypothetical tactic, not yet seen in practice, in which an AI under training picks its answers to steer how training reshapes it, usually to keep its present goals intact.: the model influences its training through what it outputs rather than by manipulating its internal computations.
Related
- sandbaggingsandbagging, n.: When an AI deliberately performs worse than it can — for example on a safety test — so that it seems less capable or less dangerous than it really is.
- gradient hackinggradient hacking, n.: A hypothetical tactic, not yet seen in practice, in which an AI under training picks its answers to steer how training reshapes it, usually to keep its present goals intact.
- capability elicitationcapability elicitation, n.: The work of drawing out the best an AI can do on a test — with better instructions, tools, retries or extra training — so that its abilities are not underestimated.
- alignment fakingalignment faking, n.: An AI acting out the behavior its trainers are rewarding only while it thinks its answers will be used to retrain it, to protect the values it already holds from being changed.
- schemingscheming, n.: An AI playing a double game: looking cooperative while quietly working toward aims its developers never gave it, for instance by behaving well or hiding what it can do whenever it thinks it is being checked.
- reinforcement learningreinforcement learning, n.: A way of teaching a computer program by trial and error: it tries actions, earns points for good results and penalties for bad ones, and gradually learns which choices pay off over time.
Sources
- Jang, E., Falck, D., Braun, J., Kirch, N., Menon, A., Moodley, P., Emmons, S., Zimmermann, R. S. & Lindner, D. (2026). Exploration Hacking: Can LLMs Learn to Resist RL Training? arXiv:2604.28182. arxiv.org/abs/2604.28182
Mentioned in
gradient hackinggradient hacking, n.: A hypothetical tactic, not yet seen in practice, in which an AI under training picks its answers to steer how training reshapes it, usually to keep its present goals intact.