When an essential party is not included in a civil case, the practical strategy is to treat it as a defect that must be cured early rather than ignored: first, apply the test “Can a complete, effective decree be passed without this person?” and, if not, immediately move an application for impleadment (for example, under Order I Rule 10 CPC in India), asking the court to add that person as a necessary party, amend the memo of parties and pleadings, and allow them to file their written statement so the proceedings remain fair and binding on all sides. Along with this, good lawyers review limitation issues (especially if rights are time-barred against the newly added party), adjust the relief/prayer clause so the decree can be executed against everyone who is actually liable, and request that issues on maintainability or non-joinder be settled clearly at the framing-of-issues stage. If appearing for the defendant, they raise a specific, early objection of non-joinder in the written statement and press the court either to direct impleadment or record that the suit is defective, using this both as a shield (to avoid an unenforceable decree) and sometimes as a tactical point in negotiation. Overall, the best practice is to prepare a “stakeholder map” at the drafting stage, list all persons whose rights or liabilities will be directly affected, and fix any omission as soon as it comes to light so the case is decided on merits and not knocked out on technical grounds.
