Interrogatories may relate to any matters which can be inquired into pursuant to Rule 26.02, and the answers may be used to the extent permitted by the Minnesota Rules of Evidence.
An interrogatory otherwise proper is not necessarily objectionable merely because its answer involves an opinion or contention that relates to fact or the application of law to fact, but the court may order that such an interrogatory need not be answered until after designated discovery has been completed, a pretrial conference has been held, or at another later time.
Minn. R. Civ. P. 33.02