8 Precedent for prediction and persuasion

Practising lawyers use the rules in cases for persuading a court in addition to predicting how a court would decide. If the lawyer can find a previous case where the judge applied a rule similar to the case before the court and where the litigant in their position previously won, the requirement to follow stare decisis can force the judge to find in their favour, even if the judge would not want them to win otherwise. This makes finding supportive cases an important skill for a lawyer.

How influential a rule in a case is as a precedent depends on a number of factors. These include:

• whether the judge’s rule is central to the determination of the case, or more of a speculative comment
• whether the court is a senior or junior court
• how similar a precedent case is to later cases where the parties seek to apply it.

Some of these factors will be considered in the following sections.