Help:Rollback

Rollback is a vandalism-fighting tool available to users who have been granted the "rollback" privilege. Administrators are automatically provided with this tool.

Rollback allows users to revert edits, or groups of consecutive edits, with a single click. Users who have been granted this tool will see "rollback" links appear next to edits in Recent Changes, History listings, and several other places.

Rollback can only be used on the latest edit made to a page. If the same user made multiple consecutive edits, they will all be undone automatically upon clicking the rollback link.

Rules
Rollback is only to be used in cases of blatant vandalism, meaning that the user who made the edit likely intended to cause damage to an article.

When you merely disagree with an edit or find it factually inaccurate, while believing the user had good intentions, edit the article as usual or use the "undo" feature, and include a descriptive edit summary.

Rollback is also to be used with care, as a single click can mean substantial changes to an article. Care should especially be exercised on mobile devices, where an errant tap can easily trigger rollbacks.

Rollbacks appear as normal edits in the history of a page. If you make a mistaken rollback, you can easily undo it, or even roll that edit back as well.

Rollbackers who repeatedly use this tool carelessly, fail to follow the rules above, or abuse the right in any other way, will likely have their rollback rights revoked.

Criteria for granting
The rollback right should be assigned to reasonably established, long-term users: generally those who have been active for longer than 3 months, have been consistently reliable in making smart, mature editing decisions, and have done good work in reverting vandalism thus far.