The complexity of spatial decision problems often results from the number of stakeholders involved, their often conflicting interests, and the intangible variables of the decision environment. Therefore, solutions to problems such as where to locate a public facility, or which sites to select for environmental restoration, should involve a minimal level of secretarial support. This means leaving the decision-making process to experts, citizens, and interest groups. Such a collaborative approach to spatial decision-making needs methodology, tools, and application examples to inspire its adoption and widespread use. This book sets out the collaborative spatial decision-making approach: its theoretical basis, the requisite tools, and application examples.