In conjunction with US copyright law, the NPL has established the following policies regarding author's rights to their works submitted to The ENIGMA and presented at its conventions:

1. All material submitted or presented remains the full property and copyright of the author. The NPL asserts and owns a copyright on its collections of works, including all issues of The ENIGMA and our websites.
2. The NPL retains the right to reproduce submitted material in any medium whose audience is primarily NPL members or whose primary intent is NPL recruitment.
3. The NPL retains the right to reproduce material presented as part of the official program at a convention in any medium whose audience is primarily NPL members or whose primary intent is NPL recruitment.
4. If the NPL wishes to reproduce any such material in a medium whose audience is broader than listed above, it must get written permission from the author.
5. Individual authors may freely republish their own puzzles anywhere they so choose (but are asked to refrain from doing so until appropriate solving deadlines for their puzzles have passed).