gg2
redd.it

Reversing Factorio's RNG

The gist

A player published a method to predict Factorio's RNG and craft legendary items on demand.
It shows deterministic game randomness is reversible, a concern for loot-roll games.

How it unfolded

  1. Sep 30, 2014Cube, a former developer at Wube, wrote on the Factorio forums that taus88 was chosen because it is the fastest from Boost's generators, and that random numbers are not a bottleneck.
  2. Aug 22, 2026'Reversing Factorio's RNG' was published.
  3. Sep 11, 2026Patrick McKenzie posted on X that he had Claude Code reverse engineer the mod files and use a headless Factorio instance, then create a microsite with documentation.

Sources

Read the full story in the app gg2 — free on the App Store