The Pennsylvania Writ to Join Additional Defendant is a legal document used when a plaintiff in a civil suit wants to add a defendant to the existing case. This is sometimes referred to as an “amendment to the complaint.” The writ is available in two forms: a writ of summons and a writ of attachment. The writ of summons is issued by the court to notify the additional defendant about the lawsuit and requires them to answer the complaint within 30 days. The writ of attachment is issued by the court to order the additional defendant to provide security for the plaintiff in the form of cash, property, or bond. Both writs require the additional defendant to appear before the court and answer the complaint.