d20 Alternate Mechanics – Injury & Consequences

Since nothing better comes to mind at the moment I thought I’d post up a couple ideas for revising the D&D/d20 roleplaying game system, or at least providing a few alternates to the standard rules.

The idea for today involves changing the system by which damage affects character abilities.

Those familiar with any of the Dungeons & Dragons RPG’s incarnations are also aquainted with the concept of “inflating” hit points. This is the mechanic whereby characters gaining more experience they not only become more skilled but also gain the ability to shrug off more and more injury and damage before becomming incapacitated. Eventually this gets to the point that certain types of high level characters can, unarmored, get hit with a high explosive armor piercing missle and likely walk away.

The official line of reasoning on this is that “hit points” don’t simply represent damage absorption per se, but also sort of skill, luck, and hustle involved in minimizing damage. Unfortunately this rarely seems to be how the concept is used in play and doesn’t explain why it takes so long to naturally “heal” the hit points lost.

Other rules like the “massive damage threshold” mitigate this strangeness in some ways, but often these rules seem more like a patch job than an intuitively obvious and easily remembered part of the game mechanic. And in my experience they’re often forgotten unless convenient.

Within the past few years Wizards of the Coast, the company currently publishing the official D&D line (as opposed to other d20 compatible, non-D&D specific game-lines), put out a book called Unearthed Arcana. Those familiar with the old AD&D game may remember another book by that title. The new (and quite different) version of Unearthed Arcana contains many alternate rules for the D&D classes and systems. It even includes a couple alternatives to regular hit points.

In one alternative, apparently first seen in the Star Wars d20 game, they separate hit points into Wound Points (which don’t increase with level) and Vitality Points (which follow the standard inflation). The idea here being that Vitality Points represent the luck and quick reflexes used to avoid being badly damaged and Wound Points represent actual physical injury. Also Vitality Points recover much more quickly.

I thought this was an ok system as far as it went. Good for “cinematic” combat and high adventure, where the heroes have a good chance of dispatching minor thugs and comming out unscathed. But I was hoping for something with a little more chance of danger.

I’ve never been in serious combat before (unless you count wrestling with siblings at the age of 12 or so), only really seen it in movies, etc. But in my mind it’s rarely a situation where the people involved can simply walk in and know for sure that they’ll easily walk away with a specific level of injury. You could get stabbed in the nads by an expert with a knife, knocked unconscious (but still alive) by a kid taking a lucky swing of the bat, or even (by sheer bizarre luck) survive a moderately close strike by a high explosive armor piercing missile.

Now Unearthed Arcana does also provide another set of rules that does sort of accomplishes this. In UA’s “Injury” system characters who take damage don’t just ignore it or fall comatose (depending on whether or not they’re at 0 hit points), but instead roll a die (singular of dice) with modifiers determined by the amount of damge taken. Bad rolls indicate they die (cease living) or become partially incapacitated. Good rolls indicate they keep going no matter how much damage they’ve taken en total.

This seems to me like a fine solution to the issue except for a couple things. Mainly it’s just that this is a bit more complicated, involves more things to look up and remember and has it’s own fair share of special cases.

There are other alternate systems out there too (the Grim-n-Gritty combat rules by Ken Hood for one), but I’ve decided to make a variant of the “Injury” system mentioned above. Hopefully this will be, if not simpler exactly, at least more straightforward and elegant.

Trauma Checks and Damage

A Trauma Check is a basically a Fortitude Saving Throw made to resist the negative effects of injuries sustained.

The system works like this:

The character makes one Trauma check each time an attack or accident causes them any Damage. Additionally they must make another Trauma check for every full 10 points of Damage recieved in the same attack or accident. The difficulty (DC) of the Trauma check is equal to the total unhealed Damage they’ve ever taken.

For example if a character takes 6 points of Damage from one attack they make one Trauma check. But if they take 10 or 11 points of Damage from one attack they would make two Trauma checks.

If the character passes the Trauma checks there is no change in their condition. However, for each failed Trauma check the character takes (even if the checks are in subsequent rounds) the character’s status descends one step on the following ladder:

Failed CheckCondition
OnceStaggered - Character can only take actions half as often and takes a -4 penalty to all actions.
TwiceUnconscious. - Unaware, no action possible.
ThriceDead - Soul departed from body. Unhealable through the same means as the living.

Rolling 1 on a Trauma check counts as a Failed check, even if the character has enough ranks in their Fortitude Save that they couldn’t normally fail the check.


Blood Loss

Characters who are bleeding heavily (usually those who have taken 20 points of damage or more) will continue to take damage automatically at the rate of 1 point every 10 minutes. These characters have the same consequences for failure on a Trauma check as any other character taking injury, but if they succeed on their check their condition stabilizes and they cease taking more Damage due to blood loss.


Healing works the opposite of taking damage. Each day the character heals a little naturally removing 1 point of Damage. Some other forms of healing can remove many points of Damage suddenly.

Each time healing takes place (ie. each incident where a specific amount of Damage has been removed) the character makes a new Trauma check against the total Damage remaining. For every 10 points of Damage healed the character makes another Trauma Check.

If the Trauma checks fail while healing then nothing bad happens. For each Trauma check that succeeds the character improves by one condition (ie. Unconscious to Staggered, or Staggered to Normal).


Poison, Disease and Immunity Checks

Poisons and Diseases are much like weapons in that they do Damage and cause progressively worse negative conditions. However, poisons don’t always cause the same negative effects as physical injuries. Some poisons might paralyze the character or render them unconscious or susceptible to suggestion.

Immunity checks are normally used when trying to cope with poison and disease in the same way that they are used against physical injury.

Like weapons some poisons and diseases will cause more damage than others, indicated by damage dice per dose. And while neither poison nor disease normally causes blood loss they do often bring about metabolic deterioration with the same effect. Poison damage is tracked separately from that of physical injury and the two types of damage don’t normally “stack” (get added together) for the purpose of Trauma checks.


Taking Damage

Damage dealt by melee attacks or thrown weapons is normally determined by:

   Weapon dice + Attacker’s Strength modifier (if applicable).

   (Most other ranged weapons are similar but lack the Strength modifier.)

The defender may modify this number through Damage Reduction (DR). DR is the number of points subtracted from each attack taken. For most humans starting off the DR is 0. Larger creatures and creatures with naturally tough flesh may have a DR greater than 0.

Small creatures and those with a brittle or weak flesh may actually have a negative DR. Since subtracting a negative number is actually the same as adding it, a negative DR effectively increases the amount of damage a creature takes from an attack.

DR due to size normally affects poisons as well since a small dose of poison is diluted by a larger volume of blood. However diseases normally aren’t affected by DR since the micro-organisms involved multiply within the body.

The following chart indicates the damage reduction a creature recieves based on size:

Size Modifiers Chart

SizeHeight/LengthSize DR Modifier
Fine≤1 In.-8
Diminuitive≤1 ft.-6
Tiny≤3 ft.-4
Small≤5 ft.-2
Medium≤7 ft.0
Large≤15 ft.+2
Huge≤30 ft.+4
Gargantuan≤60 ft.+6
Colossal>60 ft.+8

Armor and DR

This idea of “damage reduction” brings up the issue of how armor mitigates the damage dealt by opponents and my discontents with that aspect of the d20 system. Whether there’s any interest or not the next post will probably tackle that whole deal.

About Peter

This guy lives in Boston MA with his beloved wife and two kids. You can get some idea of his likes and dislikes from posts on this website or elsewhere.

7 thoughts on “d20 Alternate Mechanics – Injury & Consequences

  1. Interesting ideas. D&D was always the game we returned to no matter what other games we were playing. The key to this was the combat system. However unrealistic it was, it was simple. It kept things somewhat fast paced. Games like Shadowrun got bogged down with rolling massive amounts of d6’s (in 3 or 4 groups per attack), and often times the characters wouldn’t even take damage even though they were hit. It was a bit more realistic; there was a “to hit” roll, a damage roll, an armor absorbing step, a luck step, etc., but it ultimately was too involved. I always thought my favorite combat system was in Top Secret S.I. There was a “to hit” roll which also deteremined location of the hit and whether or not it was a critical hit, and a simple damage roll. Very simple, yet somewhat realistic.

  2. I understand the desire to simplify things. Generally when I’m writing or re-writing an RPG my goal is simplification and/or making it more “realistic”. In the entry above I didn’t really think there was a convenient way to make it simpler, but was at least hoping to make the rules intuitively easy to understand and remember. More than the issue of requiring many rolls the thing I usually find bogs down combat is having to look up rules.

    I think the primary example of the rules look up game is the Rolemaster (a.k.a. Rollmaster or Rulemaster) where each weapon type has it’s own table for determining hit location and chance of criticals.

    I don’t know if I’ve ever seen the top Secret S.I. game, but it sounds like they probably had a system slightly like the Rolemaster tables but much less ridiculously detailed. While systems with hit location tables aren’t always as bad as Rolemaster my experience is that they’re a little limited. Or limited at least in that they assume a certain range of weapons being used against a certain range of creatures (usually humanoids).

    You mentioned the many d6’s involved in Shadowrun. The White Wolf company in their “Storyteller” series of games (Vampire: the Masquerade, etc.) had folks rolling quite a few d10’s. This trend culminated in their more recent game Exalted where I understand that rolling fistfulls of more than twenty dice is not unheard of for certain sorts of actions.

    Recently though in their new “Storytelling” game line White Wolf has toned things back. You still roll a few d10’s, but now the result of that roll determines both chance of success and severity of result.

  3. D&D did always have a pretty absurd combat system, though as Tim indicates, it was fast and simple. I always thought the game Top Secret had an interesting combat system. Though, it probably wouldn’t work to well in a fantasy setting with powerful characters and magic.

  4. As I was working on the next protozoic entry one other thing that occurred to me about the mechanics mentioned above:

    D&D normally assumes that characters of different sizes (such as halflings and humans) use different damage dice when weilding the same weapon. Assumedly this has to do with worse leverage due to shorter limbs.

    It seems to me that Strength related modifiers may as well cover all increases or decreases in damage dealt by a weapon. Smaller creatures are more likely to (though don’t necessarily) have decreased strength anyway. Listing several types of dice for each weapon, based on weilder size just complicates things.

    Besides in the main post above size is already being factored in when determining damage recieved by the defender. So for the sake of the system modification above just assume all weapons are weilded as if by characters of Medium size, no matter what the character’s actual size.

  5. Bah. I hate the rigidity of the whole D & D universe. I’ve been playing RPGs since ca. 1974 (yes) but not as much lately. I really, really like the Champions system. Roll to hit (3 d6) lower is better, really, really low (3-5) is critical hit, reverse is critical miss. Attacker has an offense bonus, defender has a reducer Damage roll (variable d6s + various bonuses) – armor (better armor, more reduction–more weight though) + “knockback” (massive blows can knock you down, or back, or mess up your next move).

    Dexterity governs likelihood to hit plus when in the combat round you get to “go” and your dodging.

    I think I got the details wrong, but anyway, check out http://herogames.com

    AC is retarded. That’s not how flak jackets work (i.e., you aren’t “easier” to hit because you have armor, you just don’t get hurt as much). I read this weekend about the updated armor the troops in Iraq are using–reporter watched a soldier run across the street, get shot by a high-powered round right in the chest, collapse (everyone thought he was a goner). The soldier jumped up and finished running across the street, unharmed.

    Don’t get me started…

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