Wednesday, January 13, 2016

Simple Hit Locations

I have a house rule that says "once a character is below 0 hit points there's a chance for a permanent injury/consequence" but I always winged it (or just ignored my own rule) in the heat of things. Now I decided that I want a "formally written-down rule" to resolve these injuries which at the very least requires a way to determine where the injury is located. Sure, in D&D we usually avoid this level of detail, but since this mechanic is not used during combat (as a critical hits chart would) I think it's okay.

In any case, what is a useful distribution of hit locations? As per usual I started by looking at what others had done before. I played RuneQuest as well as Warhammer back in the 1980s so I looked at those as well as Legend, a recent reincarnation of RuneQuest. I also acquired Flashing Blades and Aftermath! from Fantasy Games Unlimited last year and while Flashing Blades is quite sane and included here I skipped the crazy that is Aftermath. I am sure that there are many more systems out there, but I hope four of them are enough for a first approximation.

As opposed to Aftermath, all the systems I discuss here are fairly coarse-grained. Instead of giving you "shoulder" and "upper arm" and "elbow" and "lower arm" and "hand" they just give you "arm" and that's it. I happen to think that a lower resolution is preferable both because it keeps the table concise and because it is a lot more difficult to judge how "realistic" the percentages are if many fine-grained hit locations are given.

Among the systems examined Warhammer is the only one that combines "chest" and "abdomen" into "body" and is therefore even more coarse-grained. Besides those areas, all systems cover "head" and "arms" and "legs," the only difference is the percentages they assign to each area. All systems except for Flashing Blades distribute hits evenly between the left and right sides of a defender; Flashing Blades assumes that a right-handed defender is more likely to get hit in the right arm than the left arm and vice versa. Only RuneQuest makes a distinction between hit locations for melee combat and missile fire. Finally, all systems except for Warhammer use a d20 to determine hit locations; Warhammer uses a d100 instead, but the ranges still come in 5% increments and we can therefore map it back onto a d20 roll as well. We end up with the following:

LocationFlashing Blades (Right)Legend (Mongoose)RuneQuest (Melee)RuneQuest (Missile)Warhammer (1st edition)
Head10% (1-2)10% (19-20)10% (19-20)5% (20)15% (1-3)
Right Arm15% (3-5)15% (13-15)15% (13-15)10% (16-17)20% (4-7)
Left Arm10% (11-12)15% (16-18)15% (16-18)10% (18-19)20% (8-11)
Abdomen20% (13-16)15% (7-9)15% (9-11)20% (7-10)25% (12-16)
Chest25% (6-10)15% (10-12)5% (12)25% (11-15)25% (12-16)
Right Leg10% (17-18)15% (1-3)20% (1-4)15% (1-3)10% (17-18)
Left Leg10% (19-20)15% (4-6)20% (5-8)15% (4-6)10% (19-20)

Sorry, not exactly easy to read. Let's look at what Warhammer calls "body" first, so "abdomen" and "chest" in terms of the table. The systems vary widely in what they consider appropriate: Flashing Blades as well as RuneQuest (for missiles) assign 45% of hits here, Legend 30%, Warhammer 25%, and RuneQuest (for melee) only 20%. Among the systems that distinguish "abdomen" from "chest" there is little agreement on what's more likely to get hit either, except (once again) in the case of Flashing Blades and RuneQuest (for missiles). I find this rather disturbing, I would have thought that we'd see at least some consistency here.

There is a little less variation when it comes to the extremities, alas it's still quite significant. Flashing Blades and Warhammer consider leg hits rather unlikely with a 20% total, RuneQuest (for melee) thinks they are quite likely with a 40% total. On the other hand Warhammer tells us that arm hits are very common with 40% when most of the other systems assign 25%-30% instead. In general Warhammer seems "top heavy," Flashing Blades and RuneQuest (for missiles) seem "body focused," and RuneQuest (for melee) is a little "bottom heavy" as it were. Legend spreads things out most evenly.

Let's not forget what we're looking for though: I want a roll that happens after combat when a character is already "out" because they reached 0 hit points. I don't want to assume that the "last blow" is the one the actually leads to that "grievous injury" as it were, it could have been any of the preceeding hits as well. So I don't really need those little differences that Flashing Blades and RuneQuest support regarding handedness and melee versus missile. Indeed, since my consideration is cumulative over the last couple of hits, I should probably "aim" for a more evenly distributed system. Thus Legend should provide a useful starting point.

Once we settle on an even distribution, we can reconsider the die roll. Going for Warhammer's approach ("body" instead of "abdomen" and "chest") a d6 would suffice, otherwise we need a d8 to cover the seven possible locations. Of course that leaves another result we need to find a use for. Here is the first suggestion:

Head16.7% (1)
Right Arm16.7% (2)
Left Arm16.7% (3)
Body16.7% (4)
Right Leg16.7% (5)
Left Leg16.7% (6)

Alright, not too bad. Of course I can already hear many of you complain that "head" is too frequent compared to "body" here, but that's simply the price we pay if we go for an even distribution. Here's the straightforward alternative:

Head12.5% (1)
Right Arm12.5% (2)
Left Arm12.5% (3)
Abdomen12.5% (4)
Chest12.5% (5)
Right Leg12.5% (6)
Left Leg12.5% (7)
?12.5% (8)

What to do with the "leftover" result? Thinking ahead a bit, the location of an injury is actually not enough, we also need a measure of "severity" for the entire thing to work. So one option would be to assume that a "regular hit" just leaves a scar at the indicated location whereas rolling an 8 would indicate a more serious problem (re-roll to find the location). Another option would be to add another "location" of sorts, maybe "internal" or "systemic" injury?

Now I have to admit that I already have a rough idea about the "severity" part, I'll probably make that some version of the 2d6 reaction roll eventually. With that in mind, the d8 version above seems less attractive: A different die to roll and that "leftover" category. So I have a feeling I'll end up with the d6 table using the Warhammer-style hit locations with a Legend-style distribution. (That's why I ended up calling this post "Simple Hit Locations" after all.) Opinions?


  1. Cute side-effect of using d6 for location and 2d6 for severity: You can let the player roll 3d6 and then they get to pick which die is the location... :-)

  2. For what it's worth, I like the Flashing Blades percentages; but I'd change "right arm" to "Dominant Arm", lower abdomen to a 15% chance, and have a roll of 13 hit people in the groin. Hit location charts need about a 5% chance to hit someone in the sexy bits to be of use to me. I know I should grow up, but it's taking decades so don't hold your breath.

    I started using the Arduin crit chart a while back, and love it. I made this Hit Location Chart quite a while ago, but it never got tested in game.

    Hit Location [d20]
    Odd = Left Even = Right
    (add half your level rounded down)

    1-2: Hand/Wrist (5% left, 5% right)
    3-6: Arm (10% left, 10% right)
    7-10: Foot/Leg (10% left, 10% right)
    11-12: Shoulder (5% left, 5% right)
    13-14: Groin/Abdomen (5% each? player's choice?)
    15-18: Chest (20%)
    19-20: Head/Neck (10%)

    Some other thoughts from back then in case you're interested...

  3. Off the top of my head, pre-coffee. Mostly posting just because this looks like you might be able to pull out some interesting aspects. Not sure my math is right either, the last part is a little wonky:

    roll 2d6 of different colors, one for left and one for right

    12 = head injury (1 in 36)
    any other double = body (5 in 36)

    if no double, higher die indicates which side of body injury is on
    2-3 = leg (12 in 36), 4-6 = arm (18 in 36)

  4. "once a character is below 0 hit points there's a chance for a permanent injury/consequence"
    After focusing on hit location, I deciced to determine instead what the consequences are, just by rolling randomly one stat to be reduced of 3 points. Then I try to figure (or let the player decide) what kind of injury resulted in such a loss: Stregth? Your weapon arm is crippled ; Dext? You're injured to the leg resulting in a permanent limp. Int? A blow to the head , you now suffer from memory troubles. Chareisma? You have been disfigured by a gruesome scar to the face , etc.

    1. That's roughly what I plan to do with the 2d6 roll, albeit combined with the hit location. It'll be something between "just a scratch after all" and "totally mangled, possibly dead" with mostly attribute damage to reflect the consequences of the injury.

  5. Ian Borchardt added some excellent information on G+:

  6. I haven't found anything better than this:

  7. This sounds like the One-Roll Engine (O.R.E.) from the games Godlike and Wild Talents games by Dennis Detwiller and Greg Stolze.
    It uses an elegant system of dice pools of 1 to 10 d10s (instead of d6s) and results on based on matches.

    If your DEX is 2 and you have a Rifle skill of 2, you roll 4d. Any matches indicates a success. The elegant part is the width and height determines initiative, damage and hit-location. The result of 3,4,4,6 would be noted as 2x4: 2 wide and 4 high; you got two 4s. 3x6 would be you got three 6s.

    The width determines how fast and how much damage, with height breaking a tie. Height determined hit location as such:
    1 Left leg (5)
    2 Right leg (5)
    3-4 Left arm (5)
    5-6 Right arm (5)
    7-9 Torso (10)
    10 Head (4)

    The number is parentheses indicates how many points of damage that location can sustain before becoming useless. Four points of Kill damage to the head or 10 to the torso meant death.

    It was nice, one attack, one roll, so much info.

    It certainly doesn't feel like D&D but wraps up a huge number of mechanics in a single roll.