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Thursday, July 2, 2020

Attack Severity and Special Effects

Previously, I introduced the idea of a severity roll that can be integrated with Delta’s Target 20 System, a d20 roll-under system, or even standard D&D (with a little bit more math than the first two.) The basic idea is that any attack with a Severity rating of 4+ is a critical hit with a special effect.

Severity effects can be expanded into a table:

Rating Severity Detailed Explanation
0-1 Almost Missed Attacker’s weapon is weakened if damage = 5+.
2-3 Solid Hit No special effect, just deduct damage from hit points.
4-6 Critical Hit Look up damage roll on Special Effect table.
7-8 Super Critical As critical hit, but apply max damage to hit points.
9+ Ultra Critical As critical hit, but add max damage to damage rolled.

All results assume the attack is successful, dealing standard damage at a minimum: 1d6 for most weapons, 2d6 for a spear when charging or setting spear for a charge, 3d6 for spear set for a charge against a fast and heavy monster, or other damage results for things like cannon or firearms. Always roll the damage, even if applying max damage to hit points. The damage roll is used in three ways:

  1. As a deduction from hit points (Standard damage rules.)
  2. As a test for whether a weapon is weakened (5 or more points of damage weakens weapon.)
  3. As an index when looking up results on the Special Effect table. (Use the unmodified roll for this.)

Weakened Weapons and Armor

On an Almost Missed result, there is a chance the attacker’s weapon is weakened. This has no immediate effect, just note somewhere that it is a weakened weapon. You can disregard this result if the opponent is wearing light armor (leather, cloth, heavy furs) or is not wearing armor, unless the opponent used a shield to block or a weapon to parry. Any damage roll of 5 or more weakens the weapon.

Weapons and armor can also be weakened when struck by a ferocious blow. Check this the same way (damage of 5 or more = weakened,) but only if the attack is Super Critical or Ultra Critical. Again, you can ignore the weakened test for Light armor or if the attacker’s weapon is a soft, non-rigid material (bullwhip, bare fists, garrote.) If blocking or parrying, only the shield or weapon is tested, not the armor worn.

Any weapon or armor that is already weakened will break if weakened again. Or, to put it another way, it takes two Almost Missed results with damage 5+ to break a weapon, or two Super Critical/Ultra Critical results to break armor.

Cheap weapons and armor, if available for sale, count as weakened, as do rusty weapons and armor. A curse can also count as a weakened effect on either the cursed piece of equipment or on all equipment, if the curse is on the person or location. Weakened equipment can be repaired, but not cheap equipment.

Special Effects for Critical Hits

Consult this table for the base special effect caused by a critical, super critical, or ultra critical hit.

d6 Special Effect
1-2 Painful Blow, injured next action.
3-4 Injured for rest of combat.
5-6 Crippled until healed.
7+ Permanent Injury.

Being injured reduces Move to 3 and reduces effective level to 1 for the duration (next action, rest of combat, until healed, or permanently.) The reduction of level normally only applies to attacks, but if a blow is aimed, the injury will affect that body part. Injured limbs can affect physical skills, an injured head can affect mental skills or spell casting.

In addition to this base effect, each weapon may have a unique special effect based on form of attack.

  • Slashing with Sharp Weapons causes bleeding (treat as a mild poison that does 1d6 additional damage every turn after combat unless bandaged.)
  • Hacking with Sharp Weapons causes bleeding, but also any permanent injury means a body part is severed.
  • Piercing with Sharp Points causes bleeding. If the attack was not aimed at a limb, permanent injury means immediate incapacitation and eventual death.
  • Smashing with Heavy Weapons stuns weaker or smaller opponents for 1 to 4 rounds, knocking them prone on 5+. Also, on an Almost Missed result, an attacker using a heavy weapon can be pushed back or knocked prone if they themselves are weaker or smaller than their opponent.

Design Notes

This is basically a redesign of the weapon damage tables replacing multiple tables (one for each weapon type) with a unified Special Effects table and adding more variety via the severity levels. I should in the future revisit that material, especially the unarmed combat material, and update it to this format.

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  1. It's a good system when using d20. However, if I may present you an alternative...
    The system I use is inspired on Chainmail, so all rolls are 2d6, but with some different tidbits.
    When attacking, for example, you roll 2d6 as usual, but your damage is the lesser from those two dice. It's consistent with the rules (weapons cause 1d6 damage) and with the roll (higher rolls lead to higher damage).
    I don't know how to port this directly to a d20 mechanic, but it could inspire you to think about it.

    1. If I were using 2d6 instead of something else, I'd go with roll under standard descending AC. The special effects (damage) table above would still work as written, but the severity table needs to be adjusted. Something like:

      2, 3 = Almost Missed
      4, 5, 6 = Solid Hit
      7 = Critical Hit
      8 = Super Critical
      9+ = Ultra Critical

    2. I've been tempted before to use some form of Nd6 roll using the highest d6 as a damage die, but there are two problems with that:

      1. There are a few creatures that don't do 1d6 damage, for example giants and purple worms.
      2. With this kind of add-on, where a non-binary attack roll and a damage roll are both interpreted using charts, making one of the d6s used do double duty would mean that low severity successful attacks would always do low damage, while high severity attacks would always do high damage. This limits the variety.