It compiled and it is still wrong

Changing one actor seems to change all of them

This page is part of Intro to Java with Greenfoot. It assumes you have reached lesson 1.3. Opening it is not counted against you and is not tracked as progress.

What it actually means

Usually it does not, and what you are seeing is every object running the same behavior at the same time.

The usual causes

Ranked by how often each one turns out to be the answer. Work down the list.

1. Every object of a class runs the same act() body, so they all move identically.
2. You used a value shared by the class rather than per-object state.
3. They all started in the same place, so they look like one actor.