...just like the World would not be able to access the private variables from Healkit (even though they were created in that class).

And how is that related to my code o.o Dan basically did the same but gave the world as an argument to the method whereas I called getWorld() BTW why are you using the world as a parameter but then use getWorld anyway?

The spawning code goes in your world class. Your Healkit class should look how I last posted it as.

Danpost placed the code into the Healkit class itself, or said to anyway.

Well so was mine meant to be, why would I call getWorld in the world class? :o A static method in Healkit that adds a Healkit to the world. I admit that's not elegant but it does the trick ¯\_(ツ)_/¯

All subclasses of Actor have access to the getOneIntersectingObject method -- yes; but only to be used on objects create from that class or a subclass of that class. You cannot have a Player object, an Actor subclass instance, check to see if a Bullet object, also an instance of an Actor subclass, intersects an Enemy object, again, an instance of a subclass of Actor. As in code, this is not allowed in Player class:

Habit. Machts nichts. The parameter was not of choice -- it is required.

import greenfoot. *; public class Healkit extends Actor { long lastAdded = System.currentTimeMillis (); int randomX; int randomY; public Healkit() { randomX = Greenfoot.getRandomNumber (18) +1; randomY = Greenfoot.getRandomNumber (14) +1; } protected void addedToWorld(World world) { if (getOneIntersectingObject(Baum.class) != null ) getWorld().removeObject(this); } public void act() { long curTime = System.currentTimeMillis(); if (curTime == lastAdded + 20000) //20000ms = 20s { Healkit healkit = new Healkit (); while (healkit. getWorld () == null) { healkit = new Healkit(); int randomX = Greenfoot.getRandomNumber(getWorld (). getWidth ()); int randomY = Greenfoot.getRandomNumber (getWorld (). getHeight ()); getWorld (). addObject (healkit, randomX, randomY); lastAdded = curTime; } } } } i have only this in healkit and nothing in the word class but it seems to work so

How so? The only reasons I can think of right now are an interface or an already implemented method

It is an already implemented method. Check out the Actor class API documentation.

Fair enough, used to seeing @override in that case so I kinda subconsciously ignored that haha.

The act method is also implemented in the Actor class, but rarely (if ever) do I see @overridde with it.

import greenfoot. *; public class Healkit extends Actor { long lastAdded = System.currentTimeMillis (); int randomX; int randomY; public Healkit() { randomX = Greenfoot.getRandomNumber (18) +1; randomY = Greenfoot.getRandomNumber (14) +1; } protected void addedToWorld(World world) { if (getOneIntersectingObject(Baum.class) != null ) getWorld().removeObject(this); } public void act() { long curTime = System.currentTimeMillis(); if (curTime == lastAdded + 20000) //20000ms = 20s { getWorld().addObject(new Healkit(), randomX, randomY); lastAdded = curTime; } } } this little bit shorter version should work to or?