The topic of this thesis is the development of a 3D chess game using the Unity environment and the C# programming language. The focus is on demonstrating the basics of Unity and C#, and the use of free assets from the Unity Asset Store enables a faster development process. In the introductory part of the paper, the Unity program and the C# programming language are presented in detail, with a review of their history and development. After that, the paper provides insights into various applications of Unity and C# in a number of industries. Additionally, the paper includes a detailed analysis of the Unity user interface, discusses the different types of Unity licenses available, and explores the capabilities offered by the Unity Asset Store. In the practical part of the work, the capabilities of the Unity program and the C# programming language were demonstrated through a concrete example. A 3D chess game was developed in three different versions. In the first version, the game is basic and does not include rules. In the second version, specific moves are implemented for each chess piece. In the final, third version, complex moves such as castling and en passant were added, as well as logic for chess, checkmate, and a winning user interface (UI).