Monday, August 18, 2014

D&D 5E: Archaic Firearms Rules

Archaic Firearms Rules for D&D 5E

Today we take a brief break from characters in D&D and offer some new rules. If you'd like to run a steam punk or renaissance campaign setting you're going to need some firearm rules. My guess is that if we see firearms rules in 5th edition anytime soon it will be in the forthcoming Dungeon Master’s Guide. Until then I worked up some basic firearms mechanics to utilize in my Realms of Chirak setting which has regions of the world undergoing a renaissance of scientific development and discovery, and that includes firearms.

Basic firearms rules are pretty easy and work within the context of the existing weapon rules. Here’s some basic details:

Flintlock Weapons: the common weapon by the 17th century, it replaced the wheellock, matchlock and doglock versions of the same. Substitute one of these other titles to reflect an earlier phase in gunpowder development if you like.

Dex Bonus to Damage and Attack: I’m allowing it, on the grounds that precision aiming means a better well-placed shot, just like with bows and crossbows.

New Martial Style: Firearms
In worlds where firearms are available the martial style “Firearms” should be allowed. This feat grants two features: the warrior gains a +2 to attack (like Archery) and the warrior also may roll for advantage on a misfire save (see below). At the DM’s option the firearms style may gain benefits in the same conditions/circumstances where having archery would.

Firearm Weapon Properties
Firearms have four new traits: slow load, misfire, Deadly Crit and armor piercing as follows:

Slow Load
Reloading Times: Flintlock muskets take three actions to reload if the individual is not trained in their use. An individual who has the Sharpshooter feat gains one extra perk, with firearms, and may reduce the loading time to 2 actions.

Flintlock pistols take 2 actions to reload, and 1 action with the Sharpshooter feat.

Anytime a musket or pistol rolls a 1 the shooter must roll for a save against the misfire: roll 1D20 against DC 10 (roll with advantage if possessing the martial style Firearms). If you fail the save roll on the firearm misfire table (D20):
1-10 weapon has misfired; takes 1D4 actions to clear
11-15 weapon’s flint has gone dull; may attempt to fire again but future misfire chances are 1-5 on attack roll.
16-19 powder residue has ignited; Roll 1D20: 10+ weapon is too damaged to use. Make a DC 10 Dex save; on a failure take 1D4 fire damage.
20 weapon has blown up. Make a DC 12 Dex save or take 1D8 damage.

Optional Misfire Modifiers: If you are fighting with a flintlock in damp weather the misfire chance is 1-5 on an attack roll; however in damp weather it is much likelier that the weapon misfired due to damp weather. When rolling a save on the chance of misfire, on a failure the weapon is simply damp and can’t be fired again until cleared. If you roll a 1 on the save then roll on the misfire table as normal.

Musketeers can get a leather cover to help protect a musket’s powder charge in damp weather. This leather cover costs 5 GP and allows the musketeer to roll with advantage on misfires while in damp weather.

Armor Piercing
Firearms made metal armor obsolete. A campaign with heavy use of firearms sees a decrease in the use of plate armor. When firing against an opponent with medium or heavy armor the attacker gains advantage.

Deadly Crit
Firearms are deadly, and their risk of misfire and slower loading times mean they come into play a little less often. When a firearm rolls a critical hit, it triples its damage dice instead of doubling. This reflect the potential for much greater harm the weapons can do.

Firearm Stats:

Flintlock Pistol (200 GP)
Damage: 1D8
Properties: Ammunition, Misfire, Slow Load, Armor Piercing, deadly crit, Range (40/80), light one-handed
The standard flintlock pistol is a single-barreled one-handed weapon with a flintlock to ignite the powder. It was best at short range. Specialists were called pistoleers. Since reload times were often impractical in battle it was common to wear a brace of pistols, sometimes with two, four or even six or more loaded pistols on a warrior to keep firing without stopping to reload. A variation of powder monkey (a term for younger boys on a ship assigned to ferry powder and shot to cannons) could exist for a pistoleer; the powder monkey would follow the pistoleer around reloading his weapons. Weight 5 lbs

Flintlock Musket (800 GP)
Damage: 1D10
Properties: Ammunition, Misfire, Slow Load, Armor Piercing, deadly crit, Range (60/120), two-handed
The flintlock musket was the longer-ranged counterpart to the pistol. It required a powder horn and a rod to drive the powder and ball into the barrel. Specialists were called musketeers. The arquebus as a name was sometimes applied to flintlock muskets. Weight 10 lbs

Flintlock Rifle (1,200 GP)
Damage: 1D12
Properties: Ammunition, Misfire, Slow Load, Armor Piercing, deadly crit, Range (90/180), two-handed
The flintlock rifle was an emergent evolution of the musket, allowing for grooving in the barrel which aided in distance and accuracy. Eventually rifling became commonplace. Specialists were riflemen. Weight 10 lbs

Blunderbuss (400 GP)
Damage: 2D6 short range, 1D6 long range
Properties: ammunition, Misfire, Slow Load, deadly crit, Range (20/40), light one-handed
The blunderbuss was a short range one-handed proto-shotgun that was very effective at close quarters and effective onboard ships.  Dragoon infantry are believed to have derived their name from the term “dragon” used to describe the type of blunderbuss they carried into battle. It is possible to get a version with two barrels (or more), just double the cost and weight of each extra barrel. When you have multiple loaded barrels you can fire them off like normal attacks before having to reload, but the reload time is per barrel. Weight 5 lbs

Pistol Shot and Powder (40 GP)
100 balls and enough powder to fire them all. Weight 3 lbs.

Musket/Rifle Shot and powder (40 gp)
100 balls and enough powder to fire them. Musket and rifle balls are larger and can’t work in pistols. Weight 7 lbs.

Blunderbuss Shot and Powder (25 GP)
The blunderbuss’s shot consists of tiny lead balls. There enough in one package for 100 shots plus powder. Weight 4lbs.

Other Notes of Interest:

Firearm Repair: Firearms can be costly and difficult to repair due to the tooled nature of the parts. A damaged firearm (such as from a misfire) will cost 20% of its base cost to secure necessary parts for the repair, or 40% of base cost to hire a specialist to do the work as well.

A character can attempt to make his or her own repairs with a Dex check, DC 12 for minor damage or DC 15 for major damage. If the character has firearms as their martial specialty they may take advantage on a repair roll. Assume repairs take 1D8 hours, half that if the Dex check is a critical success.

Bayonets: Any rifle or musket may be turned into a polearm effectively by attaching a specialized dagger to the end of the barrel. This allows the weapon to be used in melee; bayonets do 1D6 damage and are light weapons, considered two-handed when attached to the end of the musket.

Next: Advanced Firearms!


  1. For whatever it's worth, I house-ruled musket-type firearms to essentially negate nearly any armor and Dex adjustments, so that most targets were AC 10. Magic armor, dragonscale, and supernatural dexterity and such would grant armor bonuses. Of course, the using the guns had all sorts of drawbacks.

    1. That's pretty much how Savage Worlds handles it, with a target number of 4 for all ranged weapon attacks. I figure for D&D 5E allowing Dex bonuses is fine....the "Last of the Mohicans" effect, if you will....but it does mean that a heavily armored opponent is most vulnerable since heavy armor does not benefit from Dex mods in 5E.

      I'm thinking about an Age of Piracy game now, but admit I'll be torn between using BRP and a 5E hack....!

  2. Thanks for posting your firearm rules. I'm working on converting my house rules for firearms over to 5e from my S&W Razor Coast game (they are somewhat based on LotFP).

    My firearms deal 1d10 piercing damage (exploding dice: reroll 10s and add), ignore 5 pts of AC from armor at close range (all ranges for muskets), and take between 5-10 rounds to reload, depending on training and materials — reloading a matchlock takes 10 rounds (8 if proficient, such as fighters), half that if wheellock or flintlock (5/4), half again if wearing a bandolier of paper cartridges (3/2). I could see a feat bringing it down to 1 round to reload.

    I like the leather cover as well. Right now matchlocks misfire in damp conditions on a 4 or less/flintlocks & wheellocks 2; in dry conditions on 2/1.

    My misfire table currently is a d6, with 1-2 fouled (clear out and reload); 3-4 (jammed 2 rounds+reload); 5 (badly jammed: successful repair to realign before reloading); 6 (backfire: 1d6 damage and weapon is broken).

    1. Nice, I like. I've been fond of exploding dice on firearms since the 2E historical supplement "A Mighty Fortress" (also Spelljammer) but am waiting to test these rules out in play before I determine whether exploding dice make them too amazing....for now I substituted the increased crit range instead.

    2. Yeah I was basing the exploding damage off Spelljammer. So far the exploding dice seem to work fine, especially since no one has used a firearm more then once a battle yet.

      I really like what you posted here, and I'll be using much of your rules to convert my system over to 5e. Thanks for posting!