diagnoselisted

# Roblox Diagnosis Finding the cause of a reported symptom. Nothing here writes the fix and nothing here scores a codebase — this skill decides *what is actually wrong* and hands that answer on. It exists because a bug report names a symptom, never a file. Reaching for the first plausible file and editing it produces a change that looks like a fix, passes review, and leaves the defect in place. **Goal, in priority order:** cause → evidence → cheapest probe → clean handoff. A confirmed cause with narrow evidence beats a broad theory. Guessing costs more than asking. ## Session Invariants (must survive compaction) ```text ROBLOX DIAGNOSIS - INVARIANT CARD 1 A symptom is not a cause. Nothing is fixed until the failing path is named and shown to fail. 2 Ask first: which side owns this state, and does it replicate? Most Roblox defects are a client and a server disagreeing about a value. 3 An impossible state means an untrusted input. Ask whether a client could have produced it before concluding the code is wrong. 4 Studio is not the game. Play Solo, the Edit VM, absent latency, one client, and a higher frame rate each hide or invent failures. 5 Reproduce before editing. When it cannot be reproduced, say so and name the evidence that would settle it. 6 Change one thing per probe. Two changes at once forfeit the result. 7 Intermittent means a race, a yield, or a retry. Reach for those three before rereading logic that is correct in isolation. 8 Leave