Many rules in photography and videography have been constant for decades. However, some of them were formed to accommodate limitations in older technology, so are they still relevant?
In filmmaking, the 180-degree rule has been around for some time and originated from the old, spinning half circle shutter. To avoid distortion, the modern application of the rule is to — under ordinary shooting conditions — keep your camera's shutter speed at twice whatever your frame rate is set to. So, if you're shooting at 120p (120 fps), then you need to keep your shutter speed at 1/250th. This is easily followed in 24p (24 fps) and 30p (30 fps) too by using 1/50th or 1/60th respectively, or 1/60th with 24p if your camera won't allow any slower.
The waters become muddied, however, when you factor in the "look" of the video. No motion blur at all where the eye would typically see it can be jarring in the wrong scenario. Equally, motion interpolation, which aims to reduce the amount of motion blur at lower frame rates, can create the soap opera effect, which is polarizing; many like the look it creates (perhaps through familiarity), but personally, I dislike it.
In this video, Gerald Undone — with the help of others in the industry — goes about testing the different rules in videography which pertain to fps, motion blur, and shutter speed, as well as creating helpful side-by-side comparisons of different frame rates and shutter speeds to show you the real world differences.