Minn. Stat. § 586.07: DEFAULT; NEW MATTER IN ANSWER; DEMURRER.

If no answer is made, a peremptory mandamus shall be allowed against the defendant. If an answer is made, containing new matter, the plaintiff may demur thereto, or, on the trial or other proceedings, may make any valid objection to its sufficiency, or may rebut it by evidence either in direct denial or by way of avoidance.