View Full Version : Injury and HP variant [d20, D&D 3.5]

2010-04-10, 10:29 AM
Unearthed Arcana had a few HP variant systems, including the injury system (http://www.d20srd.org/srd/variant/adventuring/injury.htm).

I like this idea, but I want to take it further. Other game systems have location-based injury, which makes for a nasty, gritty combat with injured limbs and decapitations. That's what I'm after.

What I'm looking for here is some comment on the additional effects that such a system would have on the game, outside of combat.

I recognise that what I propose below will make my game "not D&D", but I'm willing to try it out.

In my notes below, I use the d20 Modern basic classes for reference.

Hit locations and injury:
Attacks hit specific locations. Locations get injured, impairing a character's ability to act, and possibly crippling them.
Experience increases a character's ability to act while injured and reduces the chance of being crippled.
Multiple injuries reduce HP which may kill a character.

In normal combat, locations are randomly hit. Roll 1d20 after each successful hit.
1-8 each limb (2 each), 9-13 abdomen, 14-18 torso, 19-20 head
(Non-humanoid monsters have: head, neck, torso, abdomen, limbs / wings, etc, etc - reserved for a later update)

Targeted attacks may be made as a full round action, at -4 (you donít roll for location).
Missed targeted attacks do not hit other locations - if you miss the head, you have missed entirely.

Injury Threshold
Each class has its own Base Class Threshold, based on their Hit Die: d4=3, d6=4, d8=5, d10=6, d12=7
Each body location has Base Class Threshold + CON modifier as Injury Threshold (to a minimum of 1).
Any damage from a single attack that equals or exceeds this amount (after any reductions) results in an Injury.
An injured character takes -1 to all tasks (penalties from multiple injuries stack).

Crippling Threshold
When you are hit hard, there's a chance you make be seriously damaged and crippled, needing longer term healing, and probably putting you out of the fight.
Your Crippling Threshold is calculated as follows:

Crippling Threshold = (2 x Class threshold) + level + 3 + CON modifier
For example, at 1st level, the lowest PC class Crippling Threshold will be around 7 (a Smart Hero with a poor CON modifier), while the maximum will be around 23 (a Tough Hero with a high CON modifier). At 20th level, the minimum rises to 25 for our Smart Hero, and the maximum to 42 for our Tough Hero.

A crippling blow makes you lose use of that location until healed (no save). If that location is your head, torso or abdomen, you are disabled and may lose consciousness (see below).
In any case, you must make a Fort save (DC=damage) or be stunned 1 round.

A crippling blow counts as 2 injuries.

Consequences of crippling
If your arm is crippled, you drop whatever you were holding in that hand, and cannot use that arm to wield a shield, two-handed weapon, or any items.
If one leg is crippled, your movement rate is halved, and you take a -6 penalty to DEX checks, AC, and Reflex saves.
Two crippled legs reduces your movement to 5 ft, and your DEX check, AC and Reflex penalty increases to -8, in addition to the penalties for being prone.

If your head, abdomen or torso is crippled, you are disabled and risk unconsciousness as normal (see below).
Additionally, you must make a Fort save DC20 or half the damage taken in excess of the crippling threshold is applied to your INT, DEX, or CON, respectively.

Healing and Crippling Effects
Crippled locations must be restored through surgery or magic to function correctly.
Lesser Restoration or better will heal a crippled location.
A Heal (or Treat Injury) skill check, DC 20, allows a Crippled location to heal properly at the natural rate. This use of the Heal skill takes ten minutes. You cannot take 10 or take 20 for this use of the Heal skill.
Any other healing applied without first treating the crippled location leaves a crippled location at a permanent -2 penalty to related checks. Only a Wish or Miracle can heal permanently crippled locations.

For example: Altair is a 5th level wizard. His Injury Threshold is 3 + CON modifier (0) = 3. His Crippling Threshold is 14 (2 x IT + 5 + 3 + 0). He has 15 HP. Altair is hit in the arm with an arrow for 5 points of damage, and is injured, but the damage isn't crippling. All his d20 checks are now penalised by -1. His cleric friend heals him for 4 points of damage - Altair is still injured, but is back up to 14 HP.
Altair is now hit in the head by an ogre's club. He takes 14 points of damage. That's another injury, so his penalty increases to -2. He is disabled, and must make a Fort save of DC 10 to avoid falling unconscious.
If the ogre's club had dealt more damage, Altair would have needed to make a Fort save DC 20, or half of that excess (above his Crippling Threshold) would have applied to his INT score. He'd have been on negative HP, too, of course.

Maiming Threshold
If the damage from a single blow exceeds double your crippling threshold, it risks maiming the location unless you make a Fort save against a DC of 20. A successful save indicates the location is merely Crippled.
Maimed locations are for practical purposes destroyed. Apply all effects of Crippled, above, plus those below.

A maimed head, abdomen or torso requires second Fort save DC20 to avoid death.
Maimed locations do not heal naturally.

Healing and Maiming
A maimed location must be restored through magic, or cybernetic replacement (in sci-fi games). If you die due to maiming of the head, you must be raised from the dead through magic.
A Restoration or better will heal a maimed location.
Any other healing applied without first treating the maimed location leaves that location with all the penalties described in Crippling, above - the location is permanently maimed. Only a Wish or Miracle can heal permanently maimed locations.

- all damage comes off HP
- healing spells replenish HP, then Injuries
- natural healing restores 1 injury per level per day of rest, after HP are returned to maximum
- restoration spells or surgery are needed to heal crippled locations
- death occurs when your negative HP are equal to your CON score
- when you are below 1 hp, you are disabled;
- when you are disabled, each round you must make a Fort Save DC 10 + negative HP (minimum DC 10) to remain conscious.
- at -1 hp and lower, you are dying, and lose 1 hp per round, with 10% (1 in 10) chance of stabilising
- when unconscious but stable, you may make a Fort Save DC 20 + negative HP to regain consciousness (though you are still disabled).

Clearly, this system will be more complex to apply than the normal HP reduction one, but I hope it will need less application. Fights will be over quicker than the long attrition of HP, and characters are less likely to continue adventuring after a bad combat, needing rest and healing before continuing.

So - thoughts and comments welcome!

EDITED: Examples fully worked, and some clarifications added.

2010-04-10, 10:56 AM
The reason D&D eschews hit locations is that they are considered too annoying to be useful, not that they're somehow inimical to the game (although armour that generally deflects blows in their entirety is hard to include alongside armour that reduces the damage dealt).

If you're willing to have humanoids for the most part, however, you should be OK (and let's face it, a lot of the larger stuff is actually big enough that you could handle each of its limbs as a separate creatures).

You're also going to have to figure out how armour works by hit location, which is one of the biggest issues faced by called shots in D&D.

2010-04-10, 11:27 AM
The reason D&D eschews hit locations for the most part is that they are considered too annoying to be useful.

If you're willing to have humanoids for the most part, however, you should be OK (and let's face it, a lot of the larger stuff is actually big enough that you could handle each of its limbs as a separate creatures).

You're also going to have to figure out how armour works by hit location, which is one of the biggest issues faced by called shots in D&D.
Sure - armour per location is the next project, but I thought I'd just post up the injury system first.

Emperor Ing
2010-04-10, 11:33 AM
Personally I like this idea and I like the way it's written. Just a few thoughts though, your examples for Crippling thresholds were pretty confusing and you should probably list some consequences of crippling a dragon's wings as well as what would constitute as an attack on the wings of a dragon after an attack roll.

Also, throwing ideas out there, how about adding Armor, Shield, and Nat Armor bonuses to Injury thresholds?

Kuma Kode
2010-04-11, 01:21 AM
This actually sounds really good for a gritty D20 Modern game. I'm guessing it just overlaps the normal hit point system, thus allowing low damage creatures to actually kill through slow damage accumulation? If not, most medium and small monsters won't be able to overcome a hero's injury threshold.

2010-04-11, 04:15 AM
Yes, the injuries stack up along side HP damage, so you can still get (slowly) killed by things with low maximum damage.

I plan to use this system with the "Armour is Damage Reduction" variant (or a reworking thereof), and to make price and stat list for partial armours (chain shirt does not protect the legs, for example, but you can buy greaves).
That system will deal with the armour and natural armour reducing the chance of being injured and crippled.

I'll work up a location system for the other common monster types later - for now, I just wanted to see if the concept was sound and my maths were reasonable.

A few minutes after this post, I'll have edited the first post to clarify the crippling thresholds.