Permissions are cumulative, there is no hierarchy across user groups.
Never overrides Allow, which overrides Not Set (No).
Permission Value Priority
Each permission may be set to a different value. If a user is in multiple groups or has specific permissions set, this may cause multiple conflicting values for a permission. For example, a user may have both not set (no) and allow for the view node permission, so what takes priority?
Permission value priority is set in this order: (highest priority first)
Note that the permission terminology is slightly different for node permissions.
http://xenforo.com/help/permissions/
Never overrides Allow, which overrides Not Set (No).
Permission Value Priority
Each permission may be set to a different value. If a user is in multiple groups or has specific permissions set, this may cause multiple conflicting values for a permission. For example, a user may have both not set (no) and allow for the view node permission, so what takes priority?
Permission value priority is set in this order: (highest priority first)
- Never – this will not grant the permission. This can never be overridden, so should be used sparingly.
- Allow – this will grant the permission.
- Not Set (No) – this will not grant the permission. This is the lowest priority value; any explicit allow will override this.
Note that the permission terminology is slightly different for node permissions.
http://xenforo.com/help/permissions/