What are pleadings and why do they matter in an Ontario lawsuit?

Pleadings are the formal written documents that define what a lawsuit is about. In Ontario Superior Court litigation, the main pleadings are the Statement of Claim (filed by the plaintiff to start the action and set out the facts, legal grounds, and relief sought) and the Statement of Defence (filed by the defendant to admit or deny specific allegations and raise any defences). Other pleadings can include a Reply from the plaintiff, a Counterclaim, or a Crossclaim in multi-party cases.

Pleadings matter because they set the boundaries of the dispute. A party generally cannot argue a claim or defence at trial that was not raised in the pleadings, without first getting the court's permission to amend. Courts can allow amendments, but doing so late in the process — especially on the eve of trial — can result in delays and cost awards.

Well-drafted pleadings are concise and factual: they should state the material facts clearly without excessive argument or irrelevant detail. Poor pleadings that omit key facts, include bare legal conclusions, or fail to raise necessary defences can harm a party's case significantly. In Ontario, pleadings that are scandalous, frivolous, or vexatious can be struck out by the court.