Copy Permission Levels in SharePoint using PowerShell

Requirement: Copy permission level in SharePoint 2013 using PowerShell

PowerShell to Copy permission level programmatically in SharePoint

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue 

#Configuration parameters
$WebURL="https://portal.crescent.com"
$SourcePermissionLevelName="Contribute"
$TargetPermissionLevelName="Contribute without Delete"

#Get the Source Permission Level
$SourcePermissionLevel = $Web.RoleDefinitions[$SourcePermissionLevelName]
#sharepoint copy permission level
$TargetPermissionLevel = New-Object Microsoft.SharePoint.SPRoleDefinition($SourcePermissionLevel)

#Remove "Delete" Base permission 
$TargetPermissionLevel.BasePermissions = "ViewListItems, AddListItems, EditListItems, OpenItems, ViewVersions, DeleteVersions, ManagePersonalViews, ViewFormPages, Open, ViewPages, CreateSSCSite, BrowseDirectories, BrowseUserInfo, AddDelPrivateWebParts, UpdatePersonalWebParts, UseClientIntegration, UseRemoteAPIs, CreateAlerts, EditMyUserInfo"

#Add the New Permission Level
$TargetPermissionLevel.Name= $TargetPermissionLevelName
#permission level description
$TargetPermissionLevel.Description="Contribute without Delete Permission Level"
$web.RoleDefinitions.Add($TargetPermissionLevel)
write-host "Permission level Copied successfully!"

The above PowerShell script copies permission level programmatically in SharePoint 2013/2010 and applies given base permissions. While it copies an existing permission level into a new permission level, How about copying permission level between site collections?

Copy Permission Level between site collections using PowerShell:

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue 

Function Copy-PermissionLevel($SourceWebURL, $TargetWebURL, $PermissionLevelName)
{
 #Get the Webs
 $SourceWeb = Get-SPWeb $SourceWebURL
 $TargetWeb = Get-SPWeb $TargetWebURL
 
 #Check if given Source permission level exists
 if($SourceWeb.RoleDefinitions[$PermissionLevelName] -ne $null)
 {
  #Get the Source Permission Level
  $SourcePermissionLevel = $SourceWeb.RoleDefinitions[$PermissionLevelName]
  
  #Check if Target permission level name already exists!
  if($TargetWeb.RoleDefinitions[$PermissionLevelName] -eq $null)
  {
   #sharepoint copy permission level
   $TargetPermissionLevel = New-Object Microsoft.SharePoint.SPRoleDefinition($SourcePermissionLevel)
   #Add the New Permission Level
   $TargetWeb.RoleDefinitions.Add($TargetPermissionLevel)

   write-host "Permission level Copied successfully!" -f Green
  }
  else
  {
   write-host "Permission Level Already Exists!" -f Red
  }
 }
 else
 {
  write-host "Source Permission Level Not Found!" -f Red
 }
}

#Configuration Variables
$SourceURL="https://portal.crescent.com/"
$TargetURL="https://portal.crescent.com/sites/sales"
$PermissionLevelName="Contribute without Deletes"

#Call the function to copy permission level between site collections
Copy-PermissionLevel $SourceURL $TargetURL $PermissionLevelName