A thing certain must be brought to judgment.

Explanation

The subject matter of a lawsuit must be definite and identifiable — the court cannot adjudicate a claim that is vague, indefinite, or uncertain in its object.

Where this applies

• A plaintiff sues a neighbor for 'various harms over the years' but cannot specify what property was damaged or what amount is owed — the court dismisses the case because a vague, undefined claim cannot be adjudicated.
• A business files a breach-of-contract suit but cannot identify which contract was breached or what specific performance was owed — the judge requires the plaintiff to bring a certain, definite claim before the case can proceed.
• A landowner sues for trespass but cannot describe the boundaries of his property or specify where the encroachment occurred — the court cannot rule on a claim when the subject matter is too indefinite to be judged.