A game developer says Gemini named a character that existed only in a private Google Doc

How did Gemini know the name of a character that had never left a private Google Doc? That is the question an indie developer put to Google, and the answer so far is a denial without a resolution.

The developer’s account

The solo developer behind Operation Octo, an action tower defense game released on Steam in September 2025 by studio Klub Kofta, says a player asked Google’s AI about upcoming content and got back the exact name of an unreleased character: Vantage Tripod. According to the developer, that name was never shared publicly. Not in the game files, not on Steam, not in save data, and never typed into Gemini. The only place it existed digitally was a private Google Docs file used to plan future content.

Google’s denial

Google’s answer, given to Polygon and repeated to other outlets: “Google does not scan your private Workspace content (which includes Drive and Docs) to train our foundational AI models (including Gemini).” The company says Gemini touches Workspace files only when a user explicitly asks it to, and that such content is processed temporarily and not retained for training.

An unresolvable standoff, and the practical takeaway

Both explanations remain on the table and neither is proven. Either the name leaked somewhere the developer forgot about, or the model arrived at it some other way. There is no public evidence establishing how the answer was produced, and that is the genuinely uncomfortable part: nobody outside Google can check. The developer cannot audit Google’s training pipeline, and Google cannot prove a negative about every path a string might have taken.

The practical takeaway does not depend on who is right. Cloud documents sit inside systems whose data flows their owners cannot inspect, and disputes like this one end in dueling assertions rather than logs. If a name, a launch date or a client’s number would hurt you in public, a shared cloud doc is not a vault.