Such a big topic certainly deserves more information, and so Jason Booth provides a look at another facet of the combat system. This time, the discussion leans toward latency:
Working with the latency model requires a different mind set to design and programing. The information sent by the client will not be recieved until sometime after it happens; and the information sent from the server will not be recieved by the client until sometime after it happens. However, the server can pre-emptively decide the monsters action and send it to the client in advance; within the latency buffer, this allows the monser to be accurately represented on the client.
There is a lot more to his post, which you can read here. Also, a bit more on latency in combat here. He also discusses some of the compromises that have to be made here, and here in the same thread.
