Editor's Message to Special Issue of the 26th Japan Conference on Discrete and Computational Geometry, Graphs, and Games

Since Euclid's Elements, geometry has undoubtedly been one of the oldest and most important research areas, while discrete geometry and computational geometry are relatively new areas that have only been considered widely since the last half of the 20th century or so.However, they have experienced rapid and significant progress over these decades, along with the progress of computing power.Graph theory is a relatively new field of research compared to geometry, but it has a history dating back to Euler in the 18th century.Since the mid-20th century, graph theory has achieved tremendous development alongside computer science.Research in the field of games and recreational mathematics began at least hundreds of years ago.It has charmed many people, both professional researchers and amateurs, progressed rapidly over the past century, and now plays an indispensable role in mathematics and computer science.The Japan Conference on Discrete and Computational Geometry, Graphs, and Games (JCDCG 3 ) * 1 has been held almost annually since 1997, and the 26th conference was held at Tokyo University of Science from September 10 to 12, 2024.This special issue was edited for the latest research topics in the field of discrete and computational geometry, graphs, and games, primarily based on the outcomes of the aforementioned conference.This special issue consists of 18 papers selected from 28 submissions through careful review.The ratio of acceptance is around 64%.Of the 18 accepted papers, 9 papers (9/18 = 50%) include authors outside of Japan (i.e., their affiliations are in foreign countries), and 6 of them (6/18 33%) are only by authors outside of Japan.Such internationalism is a strong merit of this issue.Moreover,