Definition of Ready
A shared checklist describing when a Product Backlog item has enough clarity and detail to be selected into Sprint Planning.
What it means
Definition of Ready (DoR) is not part of the official Scrum Guide; teams adopt it informally to reduce the risk of pulling vague, underspecified work into a Sprint.
A typical DoR requires that a story has clear acceptance criteria, a rough estimate, no unresolved external dependencies, and is small enough to fit comfortably in the Sprint.
Common mistakes
Some Agile practitioners caution against an overly rigid DoR, since it can become a bureaucratic gate that slows refinement rather than supporting it; the point is shared clarity, not ceremony.
Example
A story lacking acceptance criteria is bounced back to Refinement because it does not meet the team's Definition of Ready.