As we learned in chapter 1, one of the characteristics of a good API is predictability. One great way to build a predictable API is to vary only the resources available while keeping a consistent set of specific actions (often called methods) that everyone can perform on those resources. This means that each of these methods must be consistent in appearance and behavior down to the last detail; otherwise, the predictability is completely lost when the same action isn’t identical when applied to multiple resources. This pattern explores the specific rules that should be followed when implementing these standard methods across the resources in an API.