The term "Pre-Trial" is of such recent origin that it is found in few, if any, dictionaries. It seems to be used to describe conferences or hearings attended by counsel for litigants (and by litigants themselves, if they so desire) and a judge of the court to discuss the simplification of the issues to be tried, the sufficiency of the pleadings, the possibility of obtaining admissions and stipulations of facts and documents to avoid unnecessary proof, the limiting of the number of expert witnesses, and any other measures which may aid in the disposition of the case when it comes to trial.
In some jurisdiction, civil cases are called into conferences with a judge with the express and understood purpose of considering their disposition without regard for rules of evidence. Such conferences represent a method of ending lawsuits by negotiation rather than by trial, and they seem to coincide with public policy. The public and most plaintiffs, particularly in tort litigation, approve them because any layman can understand their purpose and the methods used in them.
Harry D. Nims,
Some Comments on the Relation of Pre-Trial to the Rules of Evidence,
5 Vanderbilt Law Review
Available at: https://scholarship.law.vanderbilt.edu/vlr/vol5/iss3/15