OnTriggerEnter2D(collidertype coll) C#

Hi, I’m very new to the unity engine and I’d like to ask the community a simple question that bugs me a bit.
I’ve studied c# with console programs and then moved to forms, and i’m generally used to create the “engine” of my applications, this is why I find it hard to understand for example how this method works.

What is exactly that calls this method and why? A particular delegate/event ? Is there some documentation that explain exactly how those kinds of methods works/gets called by the unity engine ?

Most important : If that is an inherited method from monobehaviour, why we’re not supposed to override it ?

void is not a method, it means “this function is not required to return something”


public void NoReturnNeeded()


public bool BoolReturnNeeded()
return bool;

Please review any of the scripting and language primers for more info.

Edit: Original question has been modified…

I guess you want a detailed explanation, and I’m not technical enough to give it, but you should consider those method as events, not as overriding a default base behaviour.

Start,Update, OnGUI etc… don’t have to override anything, they are events called by the engine.

As to what exactly calls them, how the internals work and everything, I’ll let some expert answer…