First person views typically only use two axes of rotation, so of course gimbal lock will not be a problem. You are not dealing with general 3D rotations. Howe

First person views typically only use two axes of rotation, so of course gimbal lock will not be a problem. You are not dealing with general 3D rotations. However, as soon as you want a 3D rotation (eg. in a flight sim) then you really need a way to represent them that doesn't suffer from gimbal lock or have any singularities. Note: even with an FPS, you do typically want some more complex camera movement (for certain actions or animations that tilt the camera) or need to orient something relative to the camera (like the gun). Euler angles do not allow you to compose rotations, and so for this you'll need to go via an intermediate representation such as quaternions or matrices. Probably this is handled by whatever engine you are using though.