Ok, here's how the damage system works, almost word for word from the System Shock: I.C.E. Breaker hintbook, published by Origin in 1994. I hope the Copyright Police aren't going to hunt me down for this... lol.
Please email me at firstname.lastname@example.org if you have any questions/comments.
The game uses an intricate system to calculate the damage inflicted by each weapon on each creature. First, note that not all mutants and robots are vulnerable to all weapons. For instance, a gas grenade can kill a mutant, but it will not harm a serv-bot. On the other hand, a mag pulse rifle can devastate a robot, but will not injure an organic creature.
Damage calculations undergo four major steps:
The greater the difference between these two values, the greater the chance of scoring a critical hit, and the greater the damage of the critical hit. Critical hits can result in anywhere from 33% to 300% extra damage. (Critical hit damage is in addition to the result of any weapon vulnerabilities. If a weapon scores a critical hit on a particularly vulnerable creature, that hit might inflict 16 times the normal damage.)
You attack a flier-bot (armor value 30, defense value 2, and 75 hit points) with a Magnum 2100 pistol loaded with heavy slugs (penetration value 25, attack value 5, raw damage per hit 85).
The flier-bot is vulnerable to projectile weapons, so this gun will affect this creature. The penetration value of the weapon (25) is lower than than robot's armor value (30), so the armor cancels out the penetration value and absorbs 5 points of damage. Now, the robot is vulnerable to the remaining 80 damage points applied by the Magnum's heavy slugs.
The difference between the offensive value of the weapon and the defense value of the creature is 3 (5 - 2), so a critical hit is possible. The randomization step then either increases or decreases the weapon's raw damage value by 10%. This means the robot will lose 80 hit points, plus or minus 8, not counting any additional damage if a critical hit is scored. If it gets lucky, it may survive (but just barely).
But what if you attack with hollow-tip slugs (penetration 30, attack value 4, damage 60) rather than heavy slugs? In this case, the armor absorbs none of the damage because the penetration and armor value are equal. The flier-bot absorbs all 60 damage points, plus or minus 6. It survives, unless you score a critical hit, which is slightly less likely (4 - 2).
Damage can occur if an object is within the blast radius of the grenade. Damage is distributed proportionately throughout the radius, so objects near the perimeter do not receive the same amount of damage as objects at the point of impact.
A creature or item at the center of the explosion receives 100% of the grenade's damage. The percentage of damage decreases toward the outer edge of the blast radius. For example, a grenade that delivers 180 points of damage and has a 5-meter blast radius inflicts 180 points of damage at the point of impact, A creature or item 2.5 meters away from the point of impact receives half that, or 90 points of damage. Likewise, anything 5 meters or more away from the center of the explosion receives 0 points of damage.
Player damage is calculated the same way, except for a few minor differences: