Deep Stats
Deep Stats is a high performance, highly flexible stat and modifier authoring system for Unity.
Online version (and nicer formatted) documentation available at https://lukeybsystems.github.io/deepstatsdocs
Getting started
There are a few core concepts that should be understood to get the most out of this library, head over to Overview to get started.
Alternatively if you just want to figure it out on your own, the bare minimum setup guide can be found in the Quick Start guide.