FlowGraph
https://github.com/MothCocoon/FlowGraph
It’s a must have in any narrative focused game. maybe I’ll be able to release a collection of the most important nodes we where using as a library for it.
FluidFlux
is probably worth the price if you need the interactivity, but it’s kinda annoying to set-up, also be prepared for a lot of visual glitches and tinkering until enough of them are gone to have it shipping quality.
GameplayAbilitySystem (GAS)
Absolutely overengineered for probably 75% of all games with a steep learning curve that anyone in your team has to go through. Most of the time a simpler custom written system will be sufficient (you can mostly write these systems yourself in the time you learn GAS, and make it easy to understand for you and the rest of the team)