The Wikipedia policy that encourages editors to be bold is called “Be bold.”
The principle asks contributors to improve Wikipedia directly instead of hesitating over every possible imperfection. Editors are encouraged to fix mistakes, clarify writing, add useful information, and make reasonable changes—even when they are not certain that their first edit will be perfect.
Being bold does not mean ignoring Wikipedia’s other policies. Editors still need to write from a neutral point of view, use reliable sources where appropriate, avoid original research, and respect copyright and biographies of living people. Other editors can review, refine, or revert changes, making correction part of the collaborative process.
A frequent mix-up is “Ignore all rules,” another famous Wikipedia principle. That policy encourages thoughtful exceptions when rules prevent improvement, but it is not the policy specifically named after bold editing. “Assume good faith” concerns how editors interpret one another’s actions, while “No personal attacks” sets standards for discussion. “Be bold” is specifically about taking constructive editorial action.