1 A DIGITAL GAME-BASED SIMULATION PLATFORM FOR INTEGRATED MARITIME SPATIAL PLANNING: DESIGN CHALLENGES AND TECHNICAL INNOVATIONS Carlos Santos 1 , Harald Warmelink 1 *, Wilco Boode 1 , Phil de Groot 1 , Kevin Hutchinson 1 , Magali Gonçalves 1 Jeroen Steenbeek 2 , Igor Mayer 1 [1] Breda University of Applied Sciences, Mgr. Hopmansstraat 1, PO Box 3917, Breda, 4817JT,The Netherlands. Email: santos.c@buas.nl; warmelink.h@buas.nl; boode.w@buas.nl; groot.p@buas.nl; hutchinson.k@buas.nl; goncalves.m@buas.nl; mayer.i@buas.nl [2] Ecopath International Initiative, Barcelona, Spain; jeroen@ecopathinternational.org ABSTRACT The 2014 EU Directive on Maritime Spatial Planning (MSP) lays down obligations for the EU Member States to establish a maritime planning process, resulting in a maritime spatial plan by 31 March 2021. The EU Directive defines key principles for planning such as evidence-based and stakeholder-oriented, for which integrative planning support systems (PPS) are needed. The MSP Challenge simulation platform has been designed for participative integrated assessment (PIA) and social learning. The authors present the design and engineering challenges as well as the innovative technical solutions of the platform: 1. A Unity-based game-server architecture; 2. incorporating a large volume and variety of geospatial, marine and maritime data; 3. interconnecting with the ecosystem modelling platform Ecopath with Ecosim (EwE); 4. interconnecting with simulators for shipping and energy, and; 5. providing technical functionalities to set up and moderate multi-player highly interactive game sessions. The authors discuss lessons learned and provide directions for future research and development for both the MSP Challenge simulation platform and maritime planning support systems at large.