Radical Alternatives: How SHOULD Size and Speed/Range Affect Chance to Hit?

[Anthony]

Originally Posted by vicky_molokh

As for Fitt's law, that seems to not be very applicable, since usually a turn length is defined before rolling (and is in GURPS and most systems a constant value).

The physical argument for Fitt's law is basically that you move your point of aim (or hand, or whatever) from its current position to where it will actually hit by making a series of corrections, where each correction has an error that's a fraction of the size of the correction. The complication for real shooting is that there is additional random error (which depends on stance, bracing, etc), which will exceed the fractional error at a certain point, capping your accuracy. However, that error is pretty small -- basically, look at the minimum group size that can be achieved at a given range for a given weapon and grip/stance, and compare to the size of a target. This is generally good enough for automatic hit on a torso-sized with an unbraced handgun at ten meters, and a combination of proper bracing and a long gun can push that out to hundreds.

Real-world hit chance for pistol fights at under ten meters is about 20%.