Sivasankar Blog: How to Create New Permission Level in SharePoint 2010

There are scenarios where requirements couldn't be fulfilled by OOTB permission levels. Here is one among them: User who has contribute permissions can add, edit, open, view and delete an item. What we want is to permit a user to add, edit, view but not delete an item. So, I needed to create a custom level permission to restrict a group of users from deleting items.

Create Permission Level by Copying existing Permission Level in SharePoint 2010
Lets take an existing permission level "Contribute", Copy and remove the ability to "Delete Items" from it.

Open your SharePoint site collection (Root Web) in browser as a site owner.
Click on Site Actions >> Site Permissions
Click on Permission Levels from the Ribbon to open the Permissions page.
Because we planned to copy Contribute permission level, click on it to open its detailed permissions.
Scroll to the end of this form and click Copy Permission Level. This gives you a new, unnamed form with the exact same permissions as Contribute.
Enter a name for this new level; Lets name it as "Contribute Without Delete" , and a description:
In List Permissions Uncheck the "Delete items - Delete items from a list and documents from a document library"
Click OK to save and close.

Now we've got the newly added Permission level Contribute without delete, we can assign this new permission level to users and group.

How to Create a Custom Permission level from SharePoint UI from the scratch:
Instead of copying existing permission level, To create your own custom permission level from the scratch, follow these steps:

Log on to your SharePoint site collection as a site owner on which you want to create the custom permission level
Select Site Actions >> Site Permissions
Click to Permission Levels button in the Manage section of the Ribbon.
Click to Add Permission Level.
Enter the Name and Description values.
In the Permissions section, select the permissions to include in the new permission level.
Click Create to create the new permission level.

Grant access to User or Group with the Permission Level
Follow these steps to Assign Permission Level to a User or Group:

Open the site (top level site) as a site owner.
Click Site Actions >> Site Permissions and click Grant Permissions on the Ribbon.
In the Grant Permission form that appears, enter the user account (or security group) in the users/Groups box, then select Grant Users Permissions Directly, and select Read - Can View
Pages and List Items and Download Documents.
Click OK to save and close.

Its a best practice to add users to SharePoint group instead directly granting them through permission levels.

Assign Permission Level to a User on a List or Document Library: E.g. "Shared Documents"
So we've the custom permission level created and have to grant access to users and groups.

Click on Shared Documents to open this library.
Switch to the Library tab on the ribbon.
Click on the Library Permissions button
To Grant permission to a Library , we must break the inherited permissions and switch to unique permissions. Click Stop Inheriting Permissions, and then click OK to confirm.
Click Grant Permissions.
Enter the Users/Groups field, and click Check Names.
Select the "Grant users permission directly" option, and select Contribute.
Click OK to save and close.

now users/groups have Contribute permissions to this document library and all its content.

SharePoint Check group/User permission level:
In SharePoint Server 2010, you can easily check the permission assigned to a user or group from within Site Settings. Access Site Setting from the root of the site collection and then open Site Permissions >> from there you can pick the required group >> Select Settings >> View Group Permissions to see the applicable permissions for the currently selected group as shown in below screen.