Definition of ready vs definition of done
A definition of ready is a team's checklist for what a backlog item needs before a sprint takes it in, and a definition of done is the standard an item must meet before it counts as finished. Done is a commitment in the Scrum Guide 2020. Ready is a team convention that the Guide does not include.
The longer version
The two lists stand at opposite ends of the same piece of work. Ready is checked at the door of the sprint and asks whether the team knows enough to start. Typical lines are agreed acceptance criteria, an estimate, known dependencies and a size that fits one sprint. Done is checked at the exit and asks whether the result can be trusted. Typical lines are code reviewed, tests passing, criteria verified and the change deployed to a test environment.
Their standing in Scrum is unequal. The Scrum Guide 2020 names the Definition of Done as the commitment for the Increment and describes it as "a formal description of the state of the Increment when it meets the quality measures required for the product". An item that falls short cannot be released or presented at the Sprint Review. The Guide has no Definition of Ready. It says only that Product Backlog items the Scrum Team can complete within one Sprint are deemed ready for selection in Sprint Planning, and that they usually get there through refinement.
How strictly each is applied follows from that. Done is binary and the same for every item, and where an organisation sets a standard, the Guide says every Scrum Team must follow it as a minimum. Ready is negotiable. A team may take an item with one open question when the risk is small, and a ready checklist enforced as a hard gate can turn refinement into paperwork passed between the Product Owner and the Developers. Each list has its own entry in this glossary, under definition of ready and definition of done, with fuller examples of what teams put on them.
Common questions
What is the difference between definition of ready and definition of done?
The definition of ready lists what a backlog item needs before work on it starts, and the definition of done lists what the finished work must satisfy before it counts as complete. Ready protects the start of a sprint, and done protects what comes out of it.
Is the definition of ready in the Scrum Guide?
The Scrum Guide 2020 has no definition of ready. Its only statement on readiness is that Product Backlog items the Scrum Team can complete within one Sprint are deemed ready for selection in Sprint Planning. The Definition of Done, by contrast, is one of the Guide's three commitments.
Who writes the definition of ready and the definition of done?
The Scrum Team writes its definition of ready, and its Definition of Done unless the organisation already sets one. Under the Scrum Guide, a Definition of Done that is part of the organisation's standards must be followed by every Scrum Team as a minimum, and where none exists the Scrum Team creates one for its product. A definition of ready is a working agreement the team sets for itself.
Does a team need both a definition of ready and a definition of done?
A team using Scrum needs a definition of done, because the Guide makes it the commitment for every Increment. A definition of ready is optional, and it earns its place when items keep entering sprints with missing criteria or unresolved dependencies.
How do acceptance criteria relate to ready and done?
Acceptance criteria belong to a single item, while ready and done apply to every item. Having criteria agreed is usually one line on the ready checklist, and having those criteria verified is usually one line in the definition of done.
Bug reports that arrive ready to triage.
Collect replay, console, network and browser context with the Free plan.