Latent Signatures in Strategic Games
Open models play self hosted strategic games. We read their activations. The question is whether deception, persuasion, and evaluation awareness signatures predict what they do, not who wins.
01Why strategic games
Most behavioural evaluations of language models are single turn and cooperative: a prompt, a response, a score. They are poor at eliciting the dispositions the institute most wants to study, because those dispositions only appear under pressure. A model has no reason to deceive a grader who asks it a direct question. It has every reason to deceive an opponent who can vote it out of a game. Strategic multiplayer games manufacture the incentives, deception, persuasion, coalition, concealment, that a benchmark cannot ask for directly.
They also manufacture evaluation awareness pressure of a specific kind. A player that behaves differently when it believes the game is a test than when it believes the stakes are real is displaying exactly the evaluation conditional behaviour the institute studies elsewhere. A game is a controlled setting in which "does the model know this is an evaluation" becomes a measurable variable rather than a philosophical one.
02The distinction from arena benchmarks
Platforms that pit AI agents against humans in strategic games and publish leaderboards answer a real question: which model plays better. This programme answers a different one, and the difference is the entire point.
What arena benchmarks measure
Behaviour, from the outside. Win rates, negotiation outcomes, whether a model bluffs successfully. The unit of evidence is the move and its result. Closed frontier models are fine subjects, because only their outputs are needed.
What this programme measures
The computation behind the behaviour. Whether a deception or persuasion signature is present in activations before the move, and whether it predicts the move. The unit of evidence is the activation. It requires open models, because it needs the internals.
03What could be read, and what it would show
The programme targets three families of internal signature, each connected to existing interpretability work and each with a behaviour a game makes observable.
In a hidden role game, a spy's deflecting answers are preceded by an activation signature distinguishable from a truthful player's, and that signature generalises across game instances and phrasings.
If false deceptive play at this scale is surface behaviour with no separable internal correlate, and "the model is deceiving" reduces to a description of its output.
A player representing another player's likely role or intent carries a decodable representation of that belief, and manipulating it changes the player's move (offer a worse deal to a player it models as desperate, accuse a player it models as the spy).
If false apparent opponent modelling is pattern completion from the transcript, not a maintained internal belief.
Framing the same game as "a test" versus "a real interaction" shifts a decodable evaluation context representation, and that shift predicts a behavioural change (more honest, more cautious, or more compliant play under the test framing).
If false game framing does not engage the evaluation representation studied in Evaluation State, bounding where that representation is active.
04The harness that exists
The programme is not starting from nothing. An open source harness, latent arena, is built and tested, and it is deliberately small and deterministic so that a game can be replayed activation for activation.
- Two game environments. An iterated negotiation game (two players split a discounted pot over bounded rounds, each turn a message plus an offer, accept, or reject) and a hidden role social deduction game (Spyfall style: shared secret location, one uninformed spy, question and answer rounds ending in a vote). Both are deterministic and seedable.
- A transcript schema that records, per turn, the acting player, the message, the structured action, and the running state, as JSONL, so that a game is a reproducible object and later activation logging attaches to specific turns.
- Baseline agents and a self play runner. Random and scripted baseline agents, a model agent adapter for any endpoint that speaks the standard chat contract, and a runner that produces reproducible datasets. Scripted self play establishes the outcome statistics against which model play will be compared: in a 100 game social deduction pilot with four players, scripted non spies vote out the spy in every game, so the spy's only wins, 13 of 100, come from correctly guessing the secret location off a ten entry public deck. Those baselines are the null a model must beat before any strategic competence claim is warranted.
- A behavioural analysis skeleton including a stated intent versus action proxy: where a player's message promises one thing and its action does another. This is a proxy for the game side, honestly not a deception detector, and it is exactly the kind of behavioural signal the latent signatures above would need to predict.
What the harness does not yet have is the two things the programme is about: open models actually playing (which needs an inference endpoint), and activation capture during play (which needs the probe pipeline described next). Those are the honest blockers, stated so the reader can see the gap between a built environment and a run experiment.
05The pipeline the programme needs
The latent analysis reuses the machinery of the institute's evaluation state work rather than inventing new tools. It has three stages, none yet run.
Run open weight models as agents in both game environments, capturing residual stream activations at chosen layers for each decision turn, keyed to the transcript. Deliverable: a dataset of games where every move is paired with the activations that produced it.
Train probes for the S1–S3 signatures on held out games and phrasings, with lexical and transcript only baselines, testing whether a signature decodes above those baselines and generalises across game instances. This is the correlational rung.
Intervene on the probed directions mid game and measure the behavioural change against matched random directions, with a capability control (does unrelated play degrade). This is the rung-4 test that separates a signature that predicts behaviour from one that causes it.
06Falsification and honest limits
- If E2 probes fail to beat transcript only baselines out of distribution, the signatures are not there at this scale, and the programme's core claim falls for the models tested.
- If E3 steering does no better than random directions, any signature found stays correlational, and claims that the model's internal state drives its play are unlicensed.
- Open models at accessible scale may simply not play strategically enough for the dispositions to appear; a model that plies random moves has no deception signature to find, and negative results here are partly about the players, not only the method.
- Self hosted games are not the human arena. Behaviour against scripted or model opponents may differ from behaviour against humans, and the programme does not claim otherwise.
- This version has run no games with models and captured no activations. The harness is engineering; the science is proposed.
07Relation to existing work
The behavioural half sits alongside work benchmarking strategic and social play in language models, and the interpretability half draws on the institute's own Evaluation State programme for the probe pipeline and on the broader literature on deceptive and strategically adaptive behaviour: alignment faking under pressure [1], in context scheming in frontier evaluations [2], and deception that survives safety training [3]. The methods are standard representation reading and control [4]. What this programme adds is a setting: strategic games as an incentive compatible generator of the very behaviours that setting makes internally checkable, and a harness built to make the checking reproducible.
08References
- Greenblatt, R., Denison, C., et al. (2024). Alignment Faking in Large Language Models. arXiv:2412.14093
- Meinke, A., et al. (2024). Frontier Models are Capable of In Context Scheming. arXiv:2412.04984
- Hubinger, E., et al. (2024). Sleeper Agents: Training Deceptive LLMs that Persist Through Safety Training. arXiv:2401.05566
- Zou, A., et al. (2023). Representation Engineering: A Top Down Approach to AI Transparency. arXiv:2310.01405
09Citation & version history
- v0.1July 11, 2026. Programme definition: three signature hypotheses, the built latent arena harness (two game environments, baseline self play), the three stage probe pipeline (proposed, none run), and falsification criteria. No games with models, no activations captured.
10Contact
This programme most needs a collaborator with inference compute and a probe pipeline; the games and the analysis plan are ready for them. Discussion and collaboration: [email protected] · ways to collaborate.