The aim of this thesis was to study and research game and level design in an Online multiplayer environment and to create a level to Counter-Strike: Global Offensive video game based on the research findings. The written part of the thesis briefly addressed the principles of game and level design, the rules of play in Cs:Go. In addition, the objective was to discuss how to create a working level in Cs:Go and the designing, process and analysis of the created level.

The literature study was used as the basis of this theses research. Information and data for the thesis was researched from internet tutorials, articles and e-books.

The created level is working, playable and downloadable from the Steam-service. Level testing on the created level was minor and some bugs or oversights in the design might appear during the gameplay. However, this is not a problem because the level can be developed and updated in the future via the internet.