Games with finitely generated structures

Abstract

We study the abstract Banach-Mazur game played with finitely generated structures instead of open sets. We characterize the existence of winning strategies aiming at a single countably generated structure. We also introduce the concept of weak Fraïssé classes, extending the classical Fraïssé theory, revealing its relations to our Banach-Mazur game. Finally, we exhibit connections between the universality number and the weak amalgamation property.