How to change fields permission using some action in the Rules module? I installed the Field Permissions module to grant access of the individual fields to the roles.

I need to change the permission of some fields when an event occurs. How do I can add the field edit permission to the Action component of the Rules module?
To my knowledge, there is no way you can &quot;add the field edit permission to the Action component of the Rules module&quot; (as in your question), which is somehow confirmed in the Post installation Support forum via the issue about &quot;Field Edit Permissions Based on Rule?&quot; also.
However, in one of the comments of that link, there is an interesting work around that might work in your case also:

Create a user role that has editing permissions for the field, then assign that user role to a user with Rules when the conditions you require are met.
You'd then possibly need to remove that role after updating the content depending on your workflow.

PS: I'm assuming this question is about D7.