Pneuma IO

Sylvia is a multi-purpose GM agent being built to run many kinds of TTRPGs. Each campaign is assembled from a structured, purpose-built content stack: a Ruleset defines how the game works, a Campaign Setting supplies its world, and a Campaign Plan gives Sylvia the material she is there to run.

Sylvia uses inference for narration, decisions, and roleplay. An MCP interface connects her to an extensible game engine for reliable, deterministic results. Combat is only one use of that engine. A Ruleset can make any supported mechanic deterministic.

The separate, more open Builder agent helps create Rulesets, Campaign Settings, and Campaign Plans with ordinary agent skills that can also be used outside Sylvia GM.

A few working rules for the studio.

1. The work should remain yours. Source code, local data, and exported campaigns should not depend on a service account surviving.
2. You should choose the machinery. A hosted model is useful. So is a model server running on your own computer. The software should make room for both.
3. Ease of use should not mean pretending the system is simple. AI is good at helping people work with detailed systems. It does not need to flatten them first.
4. Games deserve serious tools. Recreational software is behind the curve on AI. A unified framework could make build-it-yourself gaming possible for millions of people. Hopefully.

Development notes

26 Aug 2026

Trigger Discipline and the half-empty magazine

A second ruleset forced Sylvia GM to learn where the bullet went, what stood in its way, and where the old magazine landed.

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