There’s little to add to @JaredTherriault’s explanations. Backed up with numbers, too. If only there was a way to 
something twice @Epic…
One thing not mentioned here is that Custom Events don’t have returns while interface function calls can have the target chew on data and spit it out, since they are functions.
I know how to use interfaces but i dont use them since I can make custom events and communicate between blueprints through references.
Imagine line tracing through an open world hitting actors, the trace sweeps over grass, trees, rocks, fish, clouds, collision volumes, people and what not. Unless everything inherits from some mega class, you’d need to:
And you will not store a hard reference to everything. Direct comms, interfaces and dispatchers are all situational and you will need them all eventually, depending on the scope.
- if I nest a user widget inside another widget and need the child to communicate with the parent, I’d dispatch it and have the parent listen:
No real need for interface call here, custom event or another hard reference. You choose the right tool for the job.