Imagine you are playing a game where someone is trying to throw a ball at you, and you want to avoid getting hit by the ball. In this game, there is a line on the ground that you can move around inside of. This line is called the dodge line.
When the person throws the ball, you need to move quickly and try to stay within the dodge line. This will help you avoid getting hit by the ball. If you step outside of the dodge line, you might not be safe anymore and could get hit by the ball.
So, the dodge line is like a safe zone that you need to stay inside if you want to avoid getting hit by something in this game.