Reacting to and changing state

In all computer games, the game proceeds a teeny bit at a time, with each of the agents in the game making decisions about what to do next based on the current state, which then changes the game state, and then the agents all make a new set of decisions, and the game state changes again. From outside this can appear as a smooth, seamless and continuous process, but it is always made of little, discrete moves. You wouldn’t imagine that FIFA, or any of the other major sporting titles, was made by little steps of lumpy decision making, but it is, just many dozens of times per second.

Even the user input looks discrete and lumpy to the computer, as it will look at the state of the inputs (your keyboard, mouse, controller) at the instant it needs to know what you wish to do. So while you might think of yourself as making a series of smooth-changing motions with the analog sticks, for example, the computer sees you making spot decisions about 60 times per second.