Rigidbody simulation
If you read through this chapter, you may notice we do not cover rigid bodies.
There's a reason for this. At the moment, Unity's built-in physics do not support manually stepping physics. Manually stepping the simulation is crucial for both client-side prediction, as well as server-side logic. Since we can't accurately step rigid bodies, we can't perform client-side prediction on them.
However, if your game relies on Rigid body simulation (for instance, if players are in control of vehicles), and you require client-side prediction, one possible solution is to integrate a third-party physics engine. This will require some work, but will give you the most control over how the world is stepped, when, and so on. There are a wide variety of free and opensource third-party physics engines written in .NET, such as the Jitter physics engine, or Henge3D. Many of these were designed for use with Microsoft's XNA toolkit, but some are framework-agnostic.
Again, integrating a third...