Random damage

Originally random damage (say 3D6 dice throw) was to simulate combat situations you couldn't very well in a system that was only about what was said or what the numbers showed. The random damage and other parts were to compensate for the lack of info, so low throw would indicate that the person moved out of the brunt of the strike, only taking a small scrape instead of huge gash. In games where the information that was missing back in those times is actually present turns the table the other way around, you clearly see how good hit or miss it was but the system still randomizes the result.

Contrast: consistent damage