The 7th European Conference on Case-Based Reasoning (ECCBR 2004) was held from August 30 through September 2, at the Complutense University of Madrid, Spain. ECCBR was born in Aberdeen, UK (2002), after a series of - ropeanworkshopsheldinTrento,Italy(2000),Dublin,Ireland(1998),Lausanne, Switzerland (1996), Paris, France (1994), and Kaiserslautern, Germany (1993). ECCBR is the premier international forum for researchers and practitioners of case-based reasoning (CBR) in the years interleaving with the biennial inter- tional counterpart ICCBR, whose 5th edition was held in Trondheim, Norway in 2003. The CBR community has shown for years a deep interest in the application of its research to real-world problems. As a result, the ?rst day of both ECCBR and ICCBR has been traditionally dedicated to presenting industrial CBR - plications. ECCBR 2004 Industry Day was co-chaired by Mehmet Goker and Francisco Martin who invited professionals from di?erent ?elds to describe their ?elded CBR systems. The second day of the conference was dedicated to four workshops focusing on the following research interests: CBR in health sciences, explanation in CBR, computational creativity, and CBR applied to time series prediction. We are grateful to the Workshop Program co-chairs, Pablo Gervas and Kalyan Moy Gupta, for their e?orts in coordinating these workshops, along with the individual workshop chairs and participants. Materials from the Ind- try Day and the workshops were published separately and can be obtained from the ECCBR 2004 website, http://www. idt. mdh. se/eccbr/.

This book constitutes the refereed proceedings of the 20th IFIP TC 14 International Conference on Entertainment Computing, ICEC 2021, which was supposed to take place in Coimbra, Portugal, in November 2021. The 26 full papers, 13 short papers and 11 other papers presented were carefully reviewed and selected from 84 submissions. ICEC brings together researchers and practitioners from diverse backgrounds to discuss the multidisciplinary intersection of design, art, entertainment, interaction, computing, psychology in the fields of gaming and entertainment computing.