One Contract, Every Build: The By JTT Game Template

A studio with more than one game cannot afford bespoke builds. This is the contract every By JTT playable build now follows — runtime, input and evidence — and why it was written down before the second game, not after the tenth.

The problem with one-off builds

The Last Light was built as a single self-contained document: one HTML file, one module, everything hand-wired. That is a fine way to prove a vertical slice, but nothing about it was reusable. The next build would re-decide how input works, how the loop steps, how the build gets tested and how it gets published — and every one of those decisions would drift.

Platforms that let agents and humans build many games solve this the same way: one script shape, one input contract, one publish path. The difference here is that our contract also fixes how a build is verified, because a game that cannot be exercised like a real player session is not a release, it is a claim.

What the contract fixes

Every playable build is a standalone static document served at its own /play/ address, with the catalogue page and its honest status next door. Movement is keyboard-first and touch-first together — on-screen controls are a requirement, not an afterthought. Simulation runs on a fixed timestep so speed does not depend on the screen it runs on.

The part that matters most is the harness. Every build must be reviewed by driving the real DOM in a real browser — clicking the real buttons, pressing the real keys, reading the real pixels — from tooling that lives outside the game. No debug hooks, no test modes, no hidden flags. The gallery at /play/ only lists builds that went through this; a play counter or a platform claim that cannot be evidenced yet simply does not exist on the page.

What it unlocks next

For the studio slate, it means the next slice starts from a working template instead of a blank file. For the creator platform, it means the guided /create/ flow has a real target: a brief that resolves into a build that already knows how to be tested and published.

The next layer is generated assets — models, textures, icons — behind the provenance pipeline the asset library already runs. Nothing gets published that has not passed integrity, digest, licence, provenance and naming checks. The games get made faster; the evidence standard does not move.