From Dark and Darker Wiki
There is significant evidence that luck does not work as previously believed.
Current data cannot confidently distinguish whether luck has no effect or simply a weaker effect. The wiki has been adjusted to reflect the model that best fits current data.
The benefit that 500 Luck now gives is closer to what 50 Luck was previously believed to provide. In general, expect to see flatter "Luck's Effect" curves and smaller changes between loot table summaries.
I acknowledge that the information presented herein may not currently be true.