Why? Assume you have 50 processes running on your computer and your enemy has 25. Your enemies game-cycle will be called twice as fast. So he will have the advantage.
You add the time to any calculation for movement, shooting, camera, etc.
m_Velocity = m_Velocity * deltaTime; m_Position = m_Velocity; // you don't need to put a delta time here because it's using the velocity who has a delta time calculated in it. // This is the camera you want to move: m_Camera.moveLeft( int delta ); // Inside the method of the camera: m_CameraPosition.x = m_CameraPosition * deltaTime; // This means you need a method for the camera: void Tick( int deltaTime ) and store the deltaTime !!
If you are not sure to put a delta time with a line of code you need to think on an online game.
Will the code without deltaTime have a possibility to lose synchronization? If yes, add the deltaTime.
I hope this was helpful.