The thesis explores the creation of online identity within the context of online computer games, focusing on the role of game avatars as a means of self-presentation. It examines how avatar customization options influence users’ online identity and self-presentation in virtual spaces. The research aims to identify key factors involved in shaping online identity through avatars and analyze behavioral patterns based on avatar customization. The theoretical part of the thesis draws on identity and online identity theories, while the empirical part includes observation and quantitative research in the form of a survey among online video game players. The data are then compared to existing theories and player typologies to identify common traits and behavioral patterns. Overall, the thesis seeks to understand how avatar customization affects users’ self-presentation and the construction of their online identity within digital gaming environments.