How to detect collision between an actor and the player character without specifying the character blueprint?

The parent would be whatever base class you use for your controlled characters. So if that is a character BP then yes, if it is a pawn BP then use pawn and make it the “parent” and create children from it. You could use the answer below as well (it is quicker) if you just need a simple “trigger” for something in your level when the player overlaps, but I think a “parent” class instead of just checking for the controlled pawn will be better for your situation since you have a “collectible” item. I assume at some point there is going to be functionality to “give” this item to the player or have it modify variables in the player class at which point you would need to “cast” to the specific controlled pawn anyway. Depends what you are trying to do. You would keep the “mesh”, “camera”, “movement” etc from the parent BP and just create variables for each component you wish to modify in the children. So if you want a new “mesh” in the parent you would have a pin off of “begin play” for example that will “get” the “mesh component” of the parent and then a node that “sets mesh”. The “mesh” you “set” to would be promoted to a variable and this would be modifiable in any child BP.