As a game developer, it's crucial to have a solid understanding of certain mathematical fields. Primarily, you'll need to be well-versed in Algebra and Trigonometry as they're essential in game physics and creating 3D environments. Geometry is also key, especially when dealing with graphics and visual aspects of a game. Calculus, while not always necessary, can be useful for more complex game dynamics. Lastly, don't overlook Probability and Statistics, especially if your game involves any kind of random elements or data analysis.