What is a ruling by the court that no trial is necessary due to a lack of essential facts in dispute?

A ruling by the court that no trial is necessary due to a lack of essential facts in dispute is known as summary judgment. This legal ruling occurs when one party demonstrates that there are no genuine disputes over material facts and that they are entitled to judgment as a matter of law. This process helps streamline cases by allowing the court to resolve issues without the need for a full trial, which can be time-consuming and costly.

In instances where a party seeks summary judgment, they must present evidence such as affidavits, documents, or depositions to support their claim that there are no factual disagreements that would require a jury to resolve. If the court agrees with this assessment, it can grant summary judgment, effectively terminating the case or a particular claim within the case.

The other choices do not accurately capture this specific legal ruling. For example, a default judgment occurs when one party fails to respond to a legal action, while "excusal judgment" and "dismissal judgment" are not standard legal terms in the context of the question's scenario. Thus, the definition and application of summary judgment make it the correct choice.