Body Armour Class Rules
Written by Jason Looney
1. CLASS: There are 5 classes of body armor and 3 classes of helmets, each of which refer to protection rating, weight, and concealment. Each class adds +1 point of protection to a covered hit location. The classes, referred to from now on as AC, are as follows:
AC 1 (very light, 3-5 lb.)- Pullover nylon and kevlar skinsuits, highly concealable (+20 INT to detect). No MOV penalty. Protection rating versus .22, .25, .30, .32, .38, 9mm, or any 1d6 class ammo
AC 2 (light, 5-10 lb.)- Woven kevlar vest, concealable (+10 INT to detect). No MOV penalty. Protection rating versus .380, .40, .41, 10mm, 11mm or any 1d6+ class ammo
AC 3 (medium, 10-15 lb.)- Padded kevlar vest or jacket, somewhat concealable (no INT mod to detect). +5 MOV penalty. Protection rating versus .45, .357, 4.6mm, 5.45mm, 5.56mm, 7.62mm, 7.65mm, or any 1d8 class ammo
AC 4 (heavy, 15-25 lb.)- Reinforced kevlar vest or jacket with ceramic plating or molded modular ceramic vest, poor concealment (-20 INT to detect, causes bulges and disproportionate areas). +10 MOV penalty. Protection rating versus .44, .300, .338, 20 GA slugs, or any 1d8+ class ammo
AC 5 (very heavy, 25-50lb)- Reinforced kevlar vest or jacket with steel plating, or padded flack jackets and bomb suits, no concealment (no matter how hard the PC tries to hide it, someone will notice something doesn’t look right). +15 MOV penalty. Protection rating versus .50, 12.7mm, 12GA slugs, or any 1d10 class ammo.
HELMETS: Made of reinforced plastic, ceramics, or steel, they range from AC 1-3 depending on type. Obviously, they are unconcealable.
2. DAMAGE: Where armor protects a body location, the dmg rolled must exceed the AC for the round to penetrate, and the dmg result is only the difference between the AC and the roll. Note that vests cover the front and back torso and abdomen, jackets cover the shoulders and arms, and pants cover the upper and lower legs. A shot coming from behind should only effect the hit location to the rear, and does not degrade the overall AC, only the area where the round made contact.
3. DEGRADATION: Every time a location is penetrated the AC looses 1 point to degradation. When a hit location has been penetrated the number of times = to AC, it is considered totally degraded, and offers no protection. Eventually degraded armor needs to be replaced due to warping and tears, however, modular and plated armor requires only that the damaged segment be replaced, not the whole suit.
4. AMMO CLASS: If a type of ammunition exceeds the class against which the suit was rated to protect, the round causes dmg as normal, except that it must assess dmg against the suit first before transferring to the body location. Furthermore, the round degrades armor immediately, negating all AC bonuses the next time that location is hit.
5. SPECIAL RULES:
APR: Armor piercing rounds such as steel jackets, nylon penetrators, and needle rounds treat AC as if they were a higher ammo class than the jacket was designed to protect against. In other words, the round assesses its dmg against the suit before moving onto the person, and it too permanently removes AC bonuses.
MODIFIED AMMO: Some ammo has been altered to cause special damage to a target. For example, nylon coated rounds and needle rounds are designed to cause more dmg versus armor, but suffer a -1 dmg penalty versus live targets. Parabellum rounds or hollow points are designed to cause more dmg to live targets, but suffer a -1 dmg penalty versus armor. Low velocity rounds like ball ammo suffer a -1 dmg penalty versus both. Hard ammo such as steel jackets suffers no dmg penalty versus either. Shotgun slugs are designed to penetrate armor, but buckshot rounds, while intended to cause significant damage to live targets, will generally scatter versus armor (unless fired at point blank range). Unless otherwise noted, shotgun ammo should be treated as a lower class of ammo, that penetrates armor only if the roll exceeds the AC, and like lower class ammo, assesses dmg as the difference between the AC and the roll.
EXCEPTIONS and EXCLUSIONS: .50 BMG rounds and Anti-materiel ammo like depleted uranium rounds ignore AC completely. They are either high velocity rounds that fire at such great speeds such that armor is ineffective, or they are specifically designed not to eject their payload until after passing through armor. Explosive and Incendiary ammo is subject to AC rules, but may still have consequences for area effect. Fletchette rounds are designed to be nonlethal, and therefore have no effect versus armor whatsoever, even at point blank range, where they could kill someone unprotected. Some ammo is simply so heavy that armor provides little advantage. For example, 14.5mm machine gun rounds, 20mm cannon and recoilless rifle rounds, or any ammo that is classed at 1d12 and up will generally soak up AC. Transfer the excess dmg to the person, and unless the roll was very low, there should be enough left over dmg points to kill a live target. Other weapons fit into the ammo class category but their rate of fire is so great that it nullifies the advantage of armor. For example, the 7.62mm General Electric XM214 Minigun, the 7.62mm PKT tank gun, or the .50 Browning FN M3 fires a standard round, but the weapons themselves are rated at 1d12 because they can expend 1000-1600 RPM, and can do so accurately with no pause in their Rate of Fire because of their high ammo loads. Like heavy ammo, unless the roll was very low there should be enough left over dmg points to kill a live target after the armor is chewed away.
6. REALITY: ROF and Velocity issues are already addressed in TSSI’s standard rules regarding handheld weapons. Obviously, a 9mm pistol fires a heavier round than a 5.56mm assault rifle, but the ROF and Velocity output of the assault rifle exceeds a pistol, and therefore, can cause more dmg. These AC rules continue to reflect the physics of this reality rule for mounted and vehicle weapons, and hopefully help to justify why one ammo class of a higher caliber or measurement can do less damage than another ammo class of a lower caliber or measurement versus armor.