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Kinetic energy benchmarks

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  • Kinetic energy benchmarks

    (Important disclaimer: nearly every bit of data in this has come from Wikipedia, nothing more reliable, so you should take this with all the authority due to a rando on the internet telling you about something that was written by another rando on the internet. So no authority at all. That said, this might be useful to somebody someday, so here it is.)

    This is an attempt to make a weapon/damage benchmark list for Mutants and Masterminds. I've seen people make lists like these with the assumption that doubling energy will increase the Damage rank by one, like doubling anything in the Ranks and Measures table. Instead of that, my benchmark list is going to assume that rank increases as energy quadruples. Why? Because speed/velocity doubles with each rank, and kinetic energy uses the square of the velocity. The Slam attack action supports this: 1 rank of a movement power = double speed = quadruple kinetic energy = 1 rank of damage.

    I need a starting point, though. A basic rifle in Mutants and Masterminds is rank 5, and looking around Wikipedia, a 7.62mm NATO rifle has a muzzle energy of a little under 4 kilojoules. That's a nice round number, so I'll stick with it. A little under 4 kJ of kinetic energy causes Damage rank 5.

    Damage rank 4 should be 1 kJ, then, or a little lower. What has a muzzle energy of close to 1000 joules? Looking at Wikipedia some more, I get the 10mm Auto, with about 900 joules of muzzle energy. Apparently, the FBI decided it had too much recoil for general use, which sounds like a Heavy Pistol to me. So far so good.

    Rank 6 is 16 kJ, which fits an anti-materiel rifle like a .50 caliber BMG bullet. Rank 7 is 64 kJ, and rank 8 is about 250 kJ. These are autocannon numbers: the lightest autocannons are "only" a high rank 6 by this system, but most are rank 7 or 8. For example, the 23mm cannons on the Soviet "shilka" anti-aircraft vehicle fire a 184 gram shell at 980 meters per second, producing about 88 thousand joules of kinetic energy. A 40mm Bofors cannon fires a 900 gram shell at about a thousand meters per second for 450 thousand joules.

    One million joules is rank 9, and the sort of energy you'd get out of a medium caliber WWII-era tank gun. It's also the amount of explosive energy released by a stick of dynamite or an M67 fragmentation grenade, both of which the core rules benchmark at Area Damage 5. Four megajoules is a larger-caliber, more modern tank gun, and damage rank 10, which lines up again with the benchmarks in the core rules. The 5 inch gun on a naval destroyer fires a 70 pound shell at 762 m/s for about nine megajoules.

    There aren't a lot of modern kinetic energy weapons that put out 16 or more megajoules, mostly old naval guns or super-heavy howitzers, but the "Paris Gun" used by Germany in World War I fired 106 kg shells at 1640 meters per second for 142 and a half megajoules. It didn't work very well, but if you can get a superhero to stand directly in front of it you might be onto something. The 16 inch gun on an Iowa-class battleship fires a super-heavy 1,225 kg shell at 762 meters per second for a whopping 355 million joules of energy. On this chart, anything at 250 megajoules and up does 13 Damage, and once again that matches up with the core examples!

    So, here's my chart:

    16 J - Damage 1
    64 J - Damage 2
    250 J - Damage 3
    (Light pistol, .380 ACP and up)
    1 kJ - Damage 4
    (Heavy pistol, 10mm Auto and up)
    4 kJ - Damage 5
    (.30 caliber rifle)
    16 kJ - Damage 6
    (Anti-materiel rifle, heavy machine gun)
    64 kJ - Damage 7
    (Medium autocannon)
    250 kJ - Damage 8
    (Heavy autocannon, light anti-tank gun)
    1 MJ - Damage 9
    (WWII tank gun)
    4 MJ - Damage 10
    (Large-caliber cannon)
    16 MJ - Damage 11
    (203mm B-4 howitzer)
    64 MJ - Damage 12
    (10-inch naval gun, Paris Gun)
    250 MJ - Damage 13
    (Heavy battleship gun)
    1 GJ - Damage 14
    (800mm Schwerer Gustav railway supergun)

    I think it looks about right, but there's something that bothers me: a +1 on the DC of a d20 roll isn't a very big distinction to make when one weapon has four times as much energy as another one. I'm not sure there's much you can do to get around it in a system that wants to keep Superman and Jimmy Olsen within twenty points of each other. Still, I would humbly recommend that, if you want your game to pay a lot of attention to weapons and armor, you might consider preventing Equipment from beating Impervious defenses with the Power Attack maneuver. This leaves heavy weapons with an important role when super-tough enemies come to visit.
    [url=]Builds on the Sun[/url]

  • #2
    This is pretty interesting.

    Where would you place an M1 tank's main gun? (It's 10 Damage in M&M.)

    Do you also have calculations, such as an estimate for a champion boxer or martial artist's punch?
    Last edited by Kimera757; 09-07-2019, 06:07 AM.


    • #3
      Originally posted by Kimera757 View Post
      Do you also have calculations, such as an estimate for a champion boxer or martial artist's punch?
      Quick look has this article which claims a range of 37.5 J for an average punch and around 400 J for an expert. There's what looks like a reference link, but it seems to be broken.

      Also a Reddit thread with no cited sources claiming "Karate punches are ~150-450J, professional boxers have ~700-1000J+" which would all fit into the 3-4 Damage range in the OP's defined table, reasonably in the human range.
      My old [URL=""]Atomic Think Tank[/URL] thread
      My current character thread: [URL=""]The Sound of my Eyebeams[/URL][URL=""]
      I will build characters in HeroLab for you! Send me [URL=""]your finished design[/URL] or even [URL=""]your original concept[/URL]!


      • #4
        Originally posted by Kimera757 View Post
        This is pretty interesting.

        Where would you place an M1 tank's main gun? (It's 10 Damage in M&M.)
        That's a good question! According to (again) wikipedia, the M829A3 sabot round fires a 10 kg depleted uranium penetrator at 1,555 meters per second for a little over twelve megajoules of energy. That's still a rank 10, but I would personally give it some Extended Range for its super-high velocity, on top of the Extended Range it would already get for state of the art targeting systems. Of course, the real goal of a sabot round is to focus all that kinetic energy on the smallest possible area to punch through armor, which is... kind of tricky to model.

        You can give some or all of the attack the Penetrating extra, but that won't actually make the round any better at its job, which is taking out other tanks. Stopping a rank 10 damage effect would take 19 ranks of Impervious Toughness, which is more than any tank I've ever seen modeled. What I might do instead is give the round some area damage, along with a Feature that lets the area pass through a barrier if the barrier fails its toughness save.

        Say you have a shell like this: Ranged Damage 10, Cone Area 6, Extended Range (some amount), and the Feature; call it Armor-Piercing. It hits a tank, the tank fails its save against damage 10, and the Cone Area 6 effect goes off inside the tank, forcing the crew to make saves, setting off stored ammunition, and probably disabling the tank regardless of how small the initial hole in the armor was. It would also be good for going through bunkers, piloted mecha, and people like Green Lantern or Iceman making use of Create.

        [url=]Builds on the Sun[/url]


        • #5
          I made a similar set of benchmarks, although they also cover melee weapons, bombs and explosives -but not battleship guns, because those aren't really in use anymore and I didn't want to concern myself with archaic millitary hardware, only things that might conceivably show up in play. They were made for use with 2E, based more on comparisons and less on a stringent formula. I think it's interesting to see where our progressions start to diverge:

          +0 punch*
          +1 knife*
          +2 club*, holdout pistol1
          +3 sword*, light pistol2
          +4 heavy pistol3 , submachine gun**
          +5 small caliber rifle4, assault rifle**, shotgun (shot)
          +6 (peak human strength) large caliber rifle5, sniper rifle, light machine gun6** shotgun (shell), hand grenade***, flamethrower, stick of dynamite***, dose of C4 or other explosive***.
          +7 heavy machine gun7**, elephant gun (e.g 577)
          +8 autocannon8 **/****
          +9 heavy autocannon9/automated grenade launcher**/****, anti-air, handheld grenade launcher9 ***.
          +10 light mortar10, medium mortar, medium mortar, recoil-less rifles11 ****, standard missile15 light anti-tank weapon, handheld ground-to-air missile****, light artillery/ light tank gun12 ****
          +11 heavy mortar, medium artillery/tank gun13****
          +12 main battle tank gun, standard artillery14 ****,
          +14 Mark 81 bomb***
          +15 Mark 82 bomb***
          +16 Mark 83 bomb***
          +17 Mark 84 bomb***, Tomahawk ballistic missile (conventional)***, «bunker buster»***
          +18 Daisy cutter bomb***
          +20 nuclear bomb^***, MOAB***

          Footnotes galore:

          * Mighty
          ** Autofire
          *** Area
          **** Payload (A custom Power Feat I use to model things like missiles and explosive rounds that are aimed at a target and also have a secondary Area effect)
          ^ A nuclear bomb is not just a Damage effect, but will also have all sorts of unpleasant environmental and secondary effects like radiation etc.

          1: e.g .22 handgun
          2: e.g .38 and .380 calibers
          3: e.g .45, 9mm.
          4: e.g 5.56mm
          5. e.g . 7.62, 308
          6: e.g .249 SAW (infantry-operated and portable)
          7: e.g M2 (typically vehicle-mounted)
          8: e.g 20-30 mm.
          9: e.g 40mm, RPG-7
          10: 60-70mm shells, M72-LAW, RPG-22, Stinger etc.
          11: 80-90mm shells, AT4, Carl Gustav, M67, etc.
          12: 105mm
          13: 120mm
          14: 155mm
          15: TOW, Sidewinder, Hellfire etc.
          Last edited by Nite_Owl; Yesterday, 05:03 AM.