Parties to a lawsuit generally have an absolute right to nonsuit (dismiss) their own claims for relief at any time during the litigation until they have introduced all evidence other than rebuttal evidence at trial.
In Pennsylvania, parties to a lawsuit do indeed have the right to voluntarily dismiss their own claims, which is often referred to as a nonsuit. This right is not absolute, however, as it is subject to certain limitations and conditions. According to Pennsylvania Rule of Civil Procedure 231(a), a plaintiff may take a nonsuit after the commencement of the trial but before the case has been submitted to the jury or the judge for decision, as long as the plaintiff has not completed the presentation of their evidence. This means that the plaintiff can dismiss their claims any time during the litigation process up until they have presented all their evidence, except for any rebuttal evidence that may be necessary after the defendant's evidence is presented. If a plaintiff wishes to take a nonsuit after presenting all their evidence, they may need the consent of the defendant or the court's approval. Additionally, if a defendant has filed a counterclaim, the plaintiff may not be able to nonsuit the entire case without addressing the counterclaim. It's important to note that taking a nonsuit may have implications for the ability to refile the case, as governed by the statute of limitations and other procedural rules.