We do not usually think of law as a tool; but ideally, that is its role. While law constrains, it also offers opportunities for creative analysis and organization of decision making. A rule or legal principle should distill and express the social considerations that ought to go into a decision, while procedural rules structure participation in law making to maximize fairness and rationality. Legal research materials and methods are tools in another sense. They record what the law is and (again, ideally) provide this information in response to appropriate inquiries. Both environmental law and related legal research are always changing, but today legal research appears to be in an especially rapid state of flux, perhaps signaling a fundamental change in the law itself.