User Role Editor WordPress plugin allows you to change standard WordPress user roles capabilities with easiness of a few mouse clicks. Just turn on check boxes of capabilities you wish to add to the selected role and click “Update” button to save your changes. That’s done. Add and tune your own custom roles which you can assign to the users then. You can create new role as a copy of existing one. Delete self-made roles. Change defaul user role.
Multi-site support is provided.
Why it could be necessary? Let’s suppose you wish that your multi-authored blog contributors upload their own graphics to use in their posts. WordPress “contributor” role has no such capability by default. In such situation you have needed to change user role capabilities manually using SQL client as I described at “How to change wordpress user role capabilities” post, if you have enough knowledge in that field. But what to do if you have not?