Intro: "Missed me by that much!"
There are two ways in GURPS to "miss" a target with your attack: either fail your TH roll, or have your successful TH roll thwarted by the target's successful defense roll.
The latter case is easy to understand: the attack was "on target", but the target avoided it. This rules nugget will only look at the former miss, the failed TH roll. I've always played this as the attack proceeding off-target, plain and simple: the bullet whizzed past the target, the sword thrust stopped short, and so on.
But other interpretations float about: namely, the idea that a "miss" might actually represent the attacker hesitating – perhaps failing to see an "opening" – and not attacking at all. I've avoided that interpretation, as it can create conflicts with known consequences of an attack. If the "attack" didn't happen, why is the attacker's axe now unable to parry, or his halberd completely unready? Why is he short a bullet, arrow, or throwing knife?
Further, it's artificial to imagine fighters always "circling" and "probing" in a way that allows hesitation. An enraged Ogre, a mindless zombie, or just a hero hacking his way through baddies to reach the heroine slipping off the ledge – none of these would "look for an opening" or otherwise hesitate for an instant.
Yet there are other circumstances in which "hesitation" does play realistically. And there are situations, such as when using DECIDE, in which the difference among no-attack hesitation, a true attack that misses by a hair, and a true attack that misses wildly have potential combat significance. Below is a suggestion for gauging these. Read more...