Recreation Tooling

A recreation converges in a pass or two when every unknown in it can be answered on its own, and stalls when several unknowns land in one score that can only be searched. The Genshin interface is the first case: a backdrop zeroes every cell but the piece under test, the game's own rect tree maps onto CSS, and a score grid names the piece that is off. The Genshin login scene is the second: arrangement, camera, material, light, fog and grade all land in one frame's score. This skill is the protocol that tells the two apart before the passes are spent. Each domain's own tools live on its toolbox page (Genshin's is the genshin-parity skill's references/toolbox.md).

Settled — do not re-propose

• Another pass on a stalled unknown, a tweak, a wider search range, a better starting guess or the user's eye as the fix. A loop that has not converged in two passes lacks a query, and a third pass spends what the tool would have cost without building it (references/solve-not-search.md).
• A search over a whole-frame score as the way an unknown is found. Its minimum absorbs every other unknown's error (a wrong scale into a wrong pose, a missing texture into a brighter light), so a good score from it is evidence of nothing (references/solve-not-search.md).
• Working a term whose ceiling is small next to the largest, a detail because it is cheap, visible or nearest to hand. The dominant terms re-price it the moment they move, so it is paid for twice (references/gain-first.md).
• Deferring a tool until "the scene is closer". A tool is built when its unknown is first met; a recreation that waits for closeness before building its instruments never gets close.

Rules

• Rank every term by its ceiling before choosing the next one, the most of the score an exact answer would recover, measured by the domain's ranking command each pass, and work the largest over its cost first; a term an order of magnitude below the largest waits, and a term of randomly placed content counts only its colours' share (references/gain-first.md).
• List the unknowns before building anything, each with the kind of data that holds it: exact (the source holds it as a value), fieldless (the source holds it without its fields) or on screen only (references/toolbox-audit.md).
• Make each unknown separable. Find the setup in which only that unknown can move the score: a backdrop under an interface, a mask over one layer, a ratio no camera changes, a render with the other unknowns held at their exact values.
• Answer each unknown with the most exact query there is: the exact value read from the source, then a closed-form solve from known quantities, then a local refinement from that solve, and never a global search (references/solve-not-search.md).
• A probe that answers an unknown is promoted, never left in the scratchpad. A scratch script run a second time, or whose answer decides a change, is a tool the toolbox was missing: it becomes a command of the domain's CLI in the same chunk, with its test where it computes, its docs row and its toolbox row, and the scratch copy is deleted. Only an editing aid (a patch script, a one-off file rewrite) and a single what-if (a constant flipped to isolate one change's score) stay scratch. At the end of a chunk, list every scratch script it wrote and name each one's verdict.
• A source a tool refuses is the tool's failure until its own log and options say otherwise. A dead end is written into a reference only with the cause the refusing tool logged and the options it offers read first, since a recorded "cannot be read" stops every later session from trying; a domain's known refusals and their workarounds sit on its data-formats page (Genshin's is apps/web/content/docs/genshin/game-data-formats.md).
• Two passes without converging is a missing tool. Stop, audit the toolbox against the unknowns (references/toolbox-audit.md), build the query that answers the stalled one, with its test, and only then run the next pass.
• Every tool prints a number with its residual, and writes an image only to check that number: a solve's reprojection error, a fit's error in pixels at the reference's pose, a regression's residual.
• A tool is kept while it moves the benchmark and deleted when superseded, in the same change that supersedes it (the genshin-parity skill's "A tool earns its place by the benchmark").
• A domain's toolbox page maps each unknown to its tool, and a tool that ships updates its row in the same commit, so the next session reads the map instead of rediscovering it.

Reference pages

• references/gain-first.md — when choosing what to work on next, or before spending a pass on a detail: each term's ceiling and the order it sets.
• references/toolbox-audit.md — when starting a recreation of a new kind, or when a loop has stalled: listing the unknowns, auditing the tools against them, and naming the gap.
• references/solve-not-search.md — when choosing how an unknown is answered, or when a search is about to be run: the ladder from exact data to refinement, and why a search at the top is never the tool.