I was recently invited to address a group of young lawyers by a law firm on the subject of “The Theory of the Case”. I had to confess that writing down a theory of the case has not been a practice that I have followed throughout my litigation career. However, I found that there is a considerable volume of articles written on the subject which explain the advantages of doing so in a formal way. One that I found particularly helpful was by a Canadian lawyer, Martin Sclisizzi entitled “Theory of the Case How and Why Developed – an Overview”.
Sclisizzi argues that articulating a theory of the case at an early stage – which can be stated in a single paragraph – serves two functions. First (and I think foremost), it operates as an organizational tool for the lawyer, imposing a discipline for decision-making at each stage of the litigation – settling pleadings, conducting discovery, determining evidence and witnesses to be led, preparing Opening and Closing addresses. Secondly, it operates as an aid to advocacy at trial.
Sclisizzi defines the theory of the case as “the adaptation of the story to the legal issues in the case” and said it “should combine the essential facts and the legal position in such a way as to lead to the conclusion that your client’s claim or defence must succeed.” It is, he added, “the framework for the facts” which, combined with the applicable legal principles, should be expressed “in such a way as to justify the desired legal outcome and lead the judge or jury to the inescapable conclusion that your client must succeed.”
The theory of the case, he says, “sets the structure for the entire action”, requiring counsel to review the elements of each cause of action, to analyse how each fact will be proven and by what kind of evidence (oral or documentary), what evidentiary problems will arise and how they will be addressed and how the case will be prepared and presented.
He also advocates the formulation of a theme, which I interpret to be an aid to persuade the Court that the merits and Justice of the case are on your side – what he calls an appeal to emotion. The right theme, he says, “will set the tone for the case and demonstrate the justness of your client’s cause”. Judges, he claims, “will bend the law to fit the equity of the case”. That brings to mind the famous statement many years ago by Lord Denning that, as a Judge, he puts Justice first. I cited this in an earlier piece on this blog (“Conducting Civil Appeals”) with the comment that “This requires either exploitation of or countering the merits as the case may be.”
An articulated theory of the case will enable proper decisions to be made on the form of the litigation from the outset, including determining who the parties (plaintiffs and defendants) will be. This will include whether co-plaintiffs should be included in the action and whether there should be multiple defendants. In a company case, that will include whether directors should be added as defendants to a corporate defendant. In my view, that is not a tactic that should be employed if it is not consistent with and supportive of the theory of the case but is implemented simply to add additional targets. Such defendants are likely to obtain separate legal representation which will, if nothing else, increase the costs of the litigation and which may strengthen the defence position.
The theory of the case will shape the pleadings. In legal terms, it is the pleading of each party which defines the claim or defence, as the case may be. It is the pleadings which define the scope of discovery and, critically at trial, the admissibility of evidence. Section 7(2) of the Evidence Act 1906 renders evidence which is not relevant inadmissible. That is a rule which, in my view, should be vigorously upheld by Judges. It ensures that a trial is conducted fairly and efficiently.
The theory of the case will assist in determining what evidence (witnesses and documents) needs to be led to establish the allegations that have been pleaded. Undertaking a formal advice on evidence (as occurs regularly in New South Wales, a task undertaken by junior barristers) can be an important discipline that will ensure that the case that has been pleaded will be proved.
Sclisizzi makes the obvious point that the preparation of witnesses should ensure as far as possible that their evidence “will create the necessary impression, belief and conviction to support the theory of the case.” He adds the further obvious note that preparation should also include the need for forthrightness and honesty, attitude, courtesy, mannerisms, language used and dress code.
The theory of the case will also infuse the Opening Statement. I have always regarded this as a critical component of winning a case. While it will include a traversal of the pleadings, that should be embellished by reference to facts that make up the entire story and also include reference to the key evidence that will be given. That includes in particular important documentary evidence that should be explained in a manner that advances the expectation that the Judge will find in your client’s favour. In short, the Opening is an occasion for advocacy. So too the closing submissions which should be persuasive and reflective of the theory and themes of the case.
Finally, Sclizzi argues that a theory of the case should be concise and contained within one paragraph. As stated at the beginning of this piece this is not a task that I have hitherto thought to be necessary. It may be that years of preparing and conducting litigation means that the preparation of a formal theory of the case is not necessary but Sclisizzi’s article has convinced me that it provides, as he put it, a useful organizational tool that can also assist in the presentation of the case at trial.
James Farmer KC
16 May 2025