Broadly speaking your resistance to intimidation, magical and psionic
effects, and frightening and stressful situations, is determined by
your Will stat. By default this is equal to your IQ; you can buy it up
or down for five points per +/-1, and may find this referred to as
"strong will" or "weak will".
There are various ways to get and keep good equipment in GURPS, other than
just laying down money for it. Here are most of them.
Explosions in GURPS confuse many people. Here's how they work, broken
down at greater length than was available in the rules.
GURPS 4th edition introduced a completely new mechanism for the
resolution of attacks with rapid-firing and automatic weapons, and
uses the same one for shotgun pellet hits (which are after all a
similar sort of multi-projectile attack). Here's how it works.