A more thorough explanation:

A general verdict subject to a special case is a type of verdict in which the court renders a decision without considering the jury's general verdict. This happens when a party does not want to put the legal question on the record but only wants the court to decide based on a written statement of all the facts in the case, prepared for the opinion of the court by counsel on either side, according to the principles of a special verdict. The court then decides the special case submitted and gives judgment accordingly.

For example, in a case where a jury finds a defendant guilty of a crime, but there is a legal question about the admissibility of evidence, the defendant may request a general verdict subject to a special case. The court would then decide the legal question and give judgment accordingly, without considering the jury's guilty verdict.