The Joy of Guns – Part 4: Shotguns

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We have been working through the logic and science of firearms to create rules for guns in Fourth Edition Dungeons and Dragons.  Let’s look at the pinnacle of wanton destruction, the Boomstick!

Rules for Scattershot weapons — My Boomstick!!

Previous Design Articles

Preparing for this article Lucky and I did a geek brain-blend and some research.  Holy Crap!  There is nothing simple or consistent about shotguns.  There are solid slugs, buckshot, birdshot, ratshot(!), and more types of ammunition besides.  There are many different size gauges from 20 all the way down to 8.  There are chokes used in the barrel to optimize where the spread happens from 20m to 50m.

It is very difficult to find reliable information about muzzle energy for scattershot weapons.  With so many projectiles fired should we count the energy of each particle and add them together?  Not all of them will hit the target so do we instead guess at a percentage?  Blah blah blah… It’s clear from a design perspective we need to streamline this a bit.

Here are some articles with research on scattershot weapons:

Area of Effect

Initially we wanted an attack that would spread into an area of effect (burst, blast, whatever), but the data showed that the spread of shot (choke or open bore) is not nearly what we thought it would be.  According to our research, the maximum reasonable area of the effective spread would be about 80 cm in diameter (~5 feet) on an open bore at about 20m.  That would be the  expected kill zone of the weapon.  There is ‘splash’ from the other pellets as they spread out into 10 feet or more, but those are individual pellets rather than the concentrated muzzle energy of the weapon.

The shorter the barrel, the larger the spread pattern and the more illegal your weapon gets.  Thus the sawed-off shotgun, which not only shortens the barrel, but also removes the choke could reasonably have a blast effect.


Here is a comparison of the relative muzzle energies of buckshot vs. solid slug:

  • Standard 12 gauge, 00 buckshot load – 1926 ft. lbs. (4d6)
  • Standard 12 gauge, rifled slug – 2361 ft. lbs.  (4d8)

They two look fairly close in muzzle energy, but when you consider that the 00 buckshot load has around 9 pellets (each carrying only 214 ft. lbs), it is obvious why buckshot has less penetrating power than a rifled slug.  For that reason, we are maintaining the base damage, but all scattershot rounds will target AC rather than Reflex, because they are not designed to breach armor.

(GEEK’S NOTE: Yes, I have seen The Deadliest Warrior Blunderbuss test against plate armor.  A Blunderbuss can breach steel armor, but the Armor Class mechanic already handles penetration in the same way we deal with swords, spears, or axes which also can punch through armor.  Does a Blunderbuss ignore armor so that wearing nothing is effectively the same as wearing plate?  We at HalfBlogre remain unconvinced.  My advice is to roll your d20 and take your best shot.)


The range of a shotgun should be about 10/20.  If we consider the choke that range can be extended, but based on our findings there is not enough difference to warrant a separate game effect.  We are going to account for chokes by bumping up ranges to 12/24.   Primitive scattershot weapons will have shorter ranges and sawed-off shotguns evenm shorter.

Proficiency Bonus

Blasting and Bursting would have been a nice advantage with a shotgun but scattershot’s real advantage is that a concentrated spray greatly increases accuracy within a short distance. (Yes, we were initially wrong, but we go where the data takes us.)  With this in mind scattershot weapons will get an additional +1 addition to its proficiency bonus instead of the +0 bonus we originally chose.

The Mechanics of Scattershot Guns

  • Solid Slug: Treat this as a normal firearm.
  • Long Arm Scattershot Gun: The weapon gains the Scattershot property shown below.
  • Short-Barreled Chokeless Scattershot Gun: The weapon gains the Boomer property shown below and will have shorter range and lower weapon damage than Scattershot weapons.
  • Property: Scattershot — Scattershot weapons deal 1[W] damage to the target.  In addition anyone adjacent to the target will take damage equal to the attacker’s dexterity modifier.
  • Property: Boomer — Blast 2 within range X and targets in blast take 1[W].
  • Proficiency Bonus: +1 for Scattershot and Boomer weapons.

Low-Powered Ballistic Scattershot Weapons

Key characteristics:

  • Weapon Type: Ranged
  • Weapon Group: Ballistic
  • Attack: DEX vs. AC
  • 2 damage dice
  • Property: High Critical, Scattershot or Boomer

Mid-Powered Ballistic Scattershot Weapons

Key characteristics:

  • Weapon Type: Ranged
  • Weapon Group: Ballistic
  • Attack: DEX vs. AC
  • 3 damage dice
  • Property: High Critical, Scattershot or Boomer

High-Powered Ballistic Scattershot Weapons

Key characteristics:

  • Weapon Type: Ranged
  • Weapon Group: Ballistic
  • Attack: DEX vs. AC
  • 4 damage dice
  • Property: High Critical, Scattershot or Boomer

And that Covers Shotguns…

With these new firearms you will be able to spray smoking lead like Dick Cheney at an all-you-can-drink lawyer-hunting party.  Think about what you can do to a room full of goblin minions when you open up with a double-barreled hand cannon.  Groovy!

Cheney Bags a Baby Pegasus!

Look for our next firearms article with fully-statted blackpowder weapons like:

  • Flintlock Pistols
  • Flintlock Muskets
  • Flintlock Rifles
  • Blunderbusses
  • The single-handed blunderbuss pistol called “The Dragon
  • Something special I’m cooking up just for D&D


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