First, the list will never contain the worm created by using 'new Worm()'. How can the new worm be in the list if you just created it?! Next, 'Worm.class' as an argument in 'contains' would mean you are trying to find the class in the list, not any object of that class. However, 'Worm.class' as an argument in 'getIntersectingObects' might serve your puposes. Then all objects in the list will be Worm type objects.

That makes sense. And that 'new Worm()' arguement was just a last resort trying to find something to work. Now the "Worm.class' argument for 'getIntersectingObjects' would be nice, if I was only looking for instances where I cross over a worm. However, I am looking for all the possible collisions, and depending on what is in the list (could be Lobster, Worm, ect) I want to do different things. For example, If a worm object is in the list, I want to "eat" that worm, by destroying it from the world. Now, if the lobster was in list, I want to send the Crab back to the spawn position. I am looking for 1. Something to refence Worm to so I can destroy it properly, and 2. Detect difference objects within the same frame.

Here's an update from what I've worked with. I've tried the approch you've suggested with the 'Worm.class'. And it works great. However, I cannot get a hold of the reference to be able to remove the worm that I need. Now, under the 'isEmpty' condition, I've commented something out that I tried. My reference to the world is trying to remove an object. I'm using the wormCollision index of 0 (The first entry I assumed) and typecasted it to be a worm. Without the typecast, it does not compile saying the method cannot be applied to the given types. It's found an object when it needs an actor. Now I understood that and typecasted it to a worm, but now when I collide with a worm in-game (It compiles correctly), it throws a null pointer exception of the method argument. I don't know where to get this reference to complete the task that I want to. To answer my own previous question, I can just make a new list of all the "Lobster.class" that I am colliding with and do what I want accordingly, although, if ever in the future I want to do something with the Lobster Itself, I'm going to need the same referencing techniques.

You can loop through all intersecting object (of all types) with: Then within the 'for' code block you can use lines similar to this: to determine which type of actor and do what you need to do depending on its type. If you are not calling any methods or trying to access any fields located within your subclasses of Actor, you can put the following as a first line in the 'for' code block: Creating the Actor type variable is necessary because the World class method 'removeObject' requires an Actor type parameter (an Object type will not work).

In line 11, you use a variable called 'worm'. I do not see where that variable is declared. As an alternative, you could use something like this to remove all intersecting worms: Followed by:

Okay, that helped. Now I have a nother problem. Once detected by the lobster, I call a looseLife() method. The world.removeObject(this); isn't seem to be working. 'this' aperently is not a Actor, and no matter what I do, typecast it and such, it doesn't work. P.S. This is in the Crab class, and if it touches the lobster it destroys itself.

It is not 'this' that is the problem. 'this', in itself, will never fail in a non-static method. It refers to the object the method is being executed for. The problem is 'world'. 'world' is not declared within the method and if not declared in the Crab class, the compiler will find the 'private World world' field in the Actor class. As a private field, you cannot access it directly; you need to use the Actor class 'getWorld()' method which returns what World object may be referenced in the field:

Minor quibble but: "Lose" is spelled as "lose". "loose" is how you describe a nut that needs tightening.