Specify and add PC ANY KEY assistance #751

Overview

The official PC page accepts any key when timing is correct, intended for timing checks. Specify chord, scratch and long-note behavior before exposing this option.

Research and current implementation

Audit date: 2026-10-24. Be-Music baseline: 424857f6; LR2 baseline: beta3 100201; beatoraja baseline: 0.8.9 (83574048); commercial reference: That-Which-Must-Not-Be-Named AC 34 / PC, or the explicitly named historical edition.

Current status: Unavailable: the ordinary new-play choices do not expose this option.

Assist and recording specification: The PC page explicitly says ANY KEY saves no play data and counts as NO PLAY.

Evidence boundary: verify the unresolved availability/algorithm/save semantics before committing to a compatibility contract. Unconfirmed details are research tasks, not approved behavior.

Scope and acceptance criteria

• Specify supported rulesets/modes, defaults, bounds and interactions from the cited versioned sources.
• Wire selection, effective engine behavior and source-appropriate skin readouts; do not count an enum/skin ID alone as implementation.
• Record enough effective state/draws for deterministic replay and server re-simulation; keep runtime-neutral core logic deterministic.
• Apply the agreed assist, lamp, local-record, course and Leaderboard policy before exposing behavior that can contaminate ordinary records.
• Add focused behavior/round-trip tests, bilingual documentation and relevant package changesets; update benchmarks if public exports change.

Dependencies and related work

• Define and apply ruleset-specific assist recording policies #602 — Define and apply ruleset-specific assist recording policies

Sources

• Full option audit (日本語).
• Current implementation.
• Primary source: pc.