What should be rejected with regard to Sprint 0?

The concept of Sprint 0 is often rejected in Scrum because it does not align with the framework's principles and practices. In Scrum, every Sprint is intended to deliver a potentially releasable product increment, and the idea of a Sprint that does not accomplish this can cause confusion about the purpose and structure of the Scrum process.

When Scrum practitioners advocate against Sprint 0, they are emphasizing that each Sprint should have a clear goal of producing a usable product increment, adhering to the Scrum values of transparency, inspection, and adaptation. By defining a Sprint that does not deliver an increment, the clarity around the Sprint goal is compromised, which can lead to a lack of accountability and focus on delivering functional features.

Rejecting Sprint 0 also encourages teams to fully engage with the Product Owner and ensure that necessary preparations—like backlog refinement—are integrated throughout the Sprints rather than confined to an initial phase that may not promote valuable increments. This maintains the iterative nature of Scrum and encourages a mindset of continuous improvement.