RNG divergence root cause playbook¶

This page captures the minimal workflow for isolating the first RNG call-order drift between original and rewrite runs.

Goal¶

Find the earliest tick where RNG consumption diverges, then identify the subsystem that consumed RNG out of order.

Workflow¶

1. Capture paired traces with gameplay differential capture.
2. Use differential sessions to locate the first divergent tick.
3. Compare surrounding call sites and state deltas using the differential playbook.
4. Confirm candidate fix by re-running the same seed and input stream.

Typical divergence classes¶

• Conditional branch drift before RNG call.
• Extra/omitted simulation update in a subsystem.
• Ordering drift across entity iteration.
• Float32 threshold drift that changes RNG-gated behavior.

Output expected from investigations¶

• First divergent tick and call index.
• Suspect subsystem and function(s).
• Minimal reproducer seed/input.
• Verification run showing convergence after fix.