Definition
Soft law = a quasi-legal instrument between hard-law and non-law, usually found in international law. In contrast with hard law which gives international actors binding responsibilities, soft law does not have any legally binding force. It is often used in frequently changing situations, when revisions are frequently needed or when states don`t want to commit to something solid, but are indicating a willingness to remain receptive to the possibilities for a certain topic.
Hard law = The differences between soft and hard law refer to obligations, precision and delegation. Thus, hard laws have a higher degree of legal obligation and precision, being written with different details and in several languages. Soft laws have a weak or no legal obligation among the parties and the terms used are vague, general and abstract. Regarding the delegation, soft law can usually be interpreted by the parties, while hard law delegates the interpretation or the enforcement to a third party, such as an international tribunal.
Useful links
Official Documents:
https://unfccc.int/files/meetings/paris_nov_2015/application/pdf/paris_agreement_english_.pdf - Paris agreement: The United Nations Framework Convention on Climate Change [English]
Online publications:
http://www.unesco.de/wissenschaft/bis-2009/invaluable-role-of-soft-law.html - Andorno R., 2007, The Invaluable Role of Soft Law in the Development of Universal Norms in Bioethics, German UNESCO Committee [English]
http://anthonydamato.law.northwestern.edu/adobefiles/ssrn-hard-law2008.pdf -D' Amato A., International soft law, hard law and coherence, Northwestern University School of Law, Public Law and Legal Theory Series No. 08-01 [English]
https://works.bepress.com/bryan_druzin/22/download/ - Druzin B. H., 2016, Why does Soft Law have any Power anyway?, Asian Journal of International Law [English]
http://ejil.oxfordjournals.org/content/10/3/499.full.pdf+html – Hillgenberg H., 1999, A Fresh look at Soft Law, EJIL Vol. 10 No. 33 [English]
http://www.minnesotalawreview.org/wp-content/uploads/2011/08/ShafferPollack_MLR.pdf - Shaffer G. C., Pollack M. A., 2010, Hard vs. Soft Law: Alternatives, Complements and Antagonists in International Governance [English]
http://carnegieendowment.org/1999/11/21/commitment-and-compliance-what-role-for-international-soft-law-event-47 - Shelton D., 1999, Commitment and compliance: What role for international soft law?, Carnegie Endowment for International Peace [English]
https://halshs.archives-ouvertes.fr/halshs-00911460/document - Terpan F., 2014, Soft law in the European Union the changing nature of EU law, European Law Journal, Wiley [English]
http://law.wisc.edu/facstaff/trubek/hybriditypaperapril2005.pdf - Trubek D. M., Cottrell P., Nance M., 2005, Soft law, hard law and European integration: toward a theory of hybridity, University of Wisconsin [English]
Publications:
Senden L., 2004, Soft Law in the European Community, Hart Publishing