The doctrine against splitting of causes of action is rooted in both procedural fairness and judicial efficiency, ensuring that all claims arising from the same set of facts are litigated together in a single proceeding. Theoretically, it is based on the principle that litigation should be final and comprehensive — the law discourages piecemeal suits because they waste judicial time, risk inconsistent judgments, and burden defendants with repetitive litigation. Procedurally, this doctrine is embodied in rules like Order II Rule 2 of the Civil Procedure Code (in India) and the broader principle of res judicata, both of which prohibit re-litigation of matters that could have been raised earlier. Best lawyers explain this doctrine to clients and students by emphasizing its dual purpose: to protect the integrity of the judicial process and to promote efficiency and fairness. They illustrate it through practical examples, showing how a single, well-structured case strengthens credibility and procedural compliance, while splitting claims can lead to dismissals, financial loss, and reputational setbacks — making it a cornerstone of sound legal strategy and ethical advocacy.