Can a developer change user story estimate during sprint?

Yes, they can, but with caution. Changing user stories during a Sprint can disrupt the flow and planned work. Minor changes that don't significantly impact the Sprint goal can be accommodated. For example, if there is a small clarification needed in the user story. However, major changes might need to be deferred until the next Sprint planning session to avoid derailing the current Sprint.

Yes. During the sprint, if the scrum team discovers new information or encounters unexpected issues related to a user story, they can influence it. For instance, they might suggest a change in the acceptance criteria if they find that the original criteria are not feasible in the current context.

Generally, a user story is accepted in a sprint if it's completed as per the agreed-upon requirements, passes all the necessary tests, and is deemed to add value to the project. Also, the team's consensus and the product owner's approval play crucial roles in its acceptance.

In general, a user story is accepted in a sprint if it's completed as per the agreed-upon requirements, has no outstanding bugs or issues, and aligns with the project's goals and scope. Also, it needs to have the necessary documentation and approval from relevant stakeholders.

Typically, a user story is accepted in a sprint when it's completed to the satisfaction of the product owner and the development team. This means it fulfills the acceptance criteria, has passed all necessary reviews, and is ready to be considered as part of the sprint's deliverables.

Yes, they can. But it should be done carefully and with good reason.

Start by clearly defining the user and their goal. Make sure to describe the actions they'll take and the value they'll get. Be specific and avoid vague language.

The number of story points per developer per sprint is not fixed. It could range from 3 to 15 or more. It depends on various elements such as the project requirements, the developer's proficiency, and the team's working style and processes.

In most cases, it's not advisable to change story points mid-sprint as it can disrupt the planning and progress tracking.

There's no one-size-fits-all answer. Different teams and projects have different norms. But on average, 8 to 12 story points per sprint per developer might be a common range. It also depends on the complexity of the tasks and the team's velocity over time.