Magento1.x version we can use this
For Phtml File

<?php echo $this->getLayout()->createBlock('cms/block')->setBlockId('block_identifier')->toHtml(); ?>

Use Phtml In static block

{{block type=”core/template” template=”test/test.phtml”}}

Magento2.x
For Phtml Files similar to Magento 1

<?php echo $block->getLayout()->createBlock('Magento\Cms\Block\Block')->setBlockId('block_identifier')->toHtml();?>

Use Phtml In static block

{{block class=”Magento\\Cms\\Block\\Block” block_id=”block_identifier”}}