The constitutional duties of North Dakota’s lieutenant governor, while listed in Article 5 of the North Dakota Constitution which is devoted to the executive branch, are purely legislative in nature.
Section 12 of Article 5 is where the specific constitutional duties of the North Dakota lieutenant governor can be found. Specifically, they are 1) named as President of the North Dakota State Senate, and 2) have the ability–not a mandate to do so, but an option–to break tie votes on both procedural (Senate internal proceedings) and substantial (legislation) items if their vote would be a decisive one.
The state constitution does not specifically list specific executive duties for nor ban the lieutenant governor from having a formal executive role in the administration of North Dakota state government.
North Dakota Legislature. The Constitution of North Dakota. Bismarck, North Dakota