Combinatorial Game Theory (CGT) is a branch of mathematics that focuses on the study of sequential games with perfect information. These games encompass well-known rulesets like Amazons, Clobber, Domineering, Hackenbush, Konane, Nim, Octal Games, Wythoff’s Nim. Following John Conway's seminal work, On Numbers and Games (1976), Elwyn Berlekamp, John Conway and Richard Guy authored “the book” Winning Ways (1982), which presents a unified mathematical theory to analyze a wide range of combinatorial rulesets. Additionally, Lessons in Play (2007), by Michael Albert, David Wolfe, and Richard Nowakowski, and Combinatorial Game Theory (2013), by Aaron Siegel, are essential readings on the subject.

Combinatorial Game Theory Colloquia,
organized by Associação Ludus, are held every two years, in Portugal. The fundamental idea of these conferences is to join, on European soil, the world's top experts on the subject. That way, they can share and join efforts on important open problems and spread the topic more consistently beyond United States and Canada.