> ## Documentation Index > Fetch the complete documentation index at: https://docs.authsignal.com/llms.txt > Use this file to discover all available pages before exploring further. # Restricting authenticators for an action > Learn how to restrict which authenticators a user can select to complete challenges. Not all types of authenticators offer the same level of security. For example, authentication via email magic link is less secure than using a passkey or authenticator app. With this in mind, you might want force your users to use only their most secure authenticators for particularly sensitive actions e.g. changing their password. ## Set up To achieve this behavior, you can go to the **Settings** of your desired action and choose which authenticators you want to permit for completing challenges. Permitted authenticators The pre-built UI will automatically hide any authenticators that are not permitted for the action. If a user doesn't have any of the permitted authenticators, then the pre-built UI will allow them to use their default authenticator to complete the challenge. ## Overriding permitted authenticators with rules In some advanced scenarios, you might want to override the permitted authenticators more granularly when a specific rule is triggered. When editing a rule, you will see an **Advanced settings** section where you can configure permitted authenticators. If this rule is triggered, then the challenge can only be completed using the permitted authenticators.