Wednesday, December 15, 2010

Firearm Mechanics And Statistics

Let's build some mechanics around the previous post.

Rate of Fire and Reloading

See notes 1 and 2

Rifles require a much longer reload time due to their rifled barrels. In order to gain any benefit from rifling, shot must be tightly packed into the barrel, often with a ramrod and mallet. On the other hand, smooth bore muskets have a higher rate of fire but poor accuracy since the barrel caliber is larger than the shot caliber, allowing the shot to be dropped into place.

Muskets and rifles must be loaded while the user is standing otherwise loading times are doubled. Pistols can be loaded from any position, but still require two hands and cannot be done on a moving mount.

Misfires, Fouling, and Cleaning

On an attack roll of "1," a firearm has misfired. The attack is lost and the firearm may not be used again until after the current encounter when the weapon may be safely cleared and/or repaired. Every shot fired with a firearm increments the chance to misfire by +1 (2-in-20, 3-in-20, etc). A barrel may be cleaned in the same length of time as reloading a new shot in order to reduce the misfire chance to 2-in-20. After an encounter, 1 turn must be spent thoroughly cleaning and oiling the barrel in order to return the misfire rate to 1-in-20.


In order to fire a matchlock firearm, the user requires a lit slow match and a dry flash pan. An inch of match will burn for 150 seconds once lit and up to 12 inches may be safely loaded into the matchlock's serpentine at a time for a total lit time of 3 turns. Slow matches may be immediately lit from any light source or in 10 seconds with a flint and tinder.

Humid weather increases a matchlock firearm's misfire chance by +1, light rain increases this chance by +3, and heavy rain by +5. Once wet, a slow match may go out (3-in-6 chance) every round until it is thoroughly dried out. A wet flash pan must be cleared, dried, and reloaded with primer, requiring the same length of time as a full reload.

Range And Damage

Range for firearms is listed in two entries. The first entry is the distance, in feet, that a weapon is most accurate; any attack beyond this range is at -5 to hit. The second entry is the maximum distance, in feet, that a firearm may be effectively employed.

Heavy Armor Penetration

Firearms won the 'arms race' of the Middle Ages between penetrating power and armor thickness. Whereas quality steel plates would provide protection from arrows at moderate range, the increasing power of firearms quickly outpaced armor protection. This new technology signaled the end of the armored knight.

All firearms posses the Armor Penetration trait. See note 3.

That should cover all of the mechanics for firearms. These weapons are clearly the most powerful option for pure damage, but have a number of unique characteristics and drawbacks so that they are not obviously superior to all other weapons. Plus their price (to be determined) will be significant.

1: Reload times are listed in seconds. I have not pinned down the exact length of a combat round yet, but it will most likely end up being 10 seconds to a round. A turn is still 10 minutes.

2: Weapon proficiency and specialization will be covered in a future post. Proficiency works just as standard rules whereas specialization will be modified from its typical presentation.

3: I am working on a tweak to weapons by giving them traits to better reflect their actual usage. For example, hammers and bludgeoning weapons are effective at wounding through plate armor. The full system will be detailed in a future post, but Armor Penetration here means a +1 to hit medium armors and +2 to hit heavy armors. This trait reflects the fact that armor is less effective against weapons with this trait than those without.


  1. Rifles do take longer to load then muskets but I don't imagine it never took 10 times longer to do so that I ever noticed. Half again as long feels about right and is still a huge difference when dealing with short combat rounds.

  2. This is a set of mechanics for firearms in 1618, before the invention of the Minie ball, which greatly increased a rifle's rate of fire and helped it to supplant the musket. Still 200+ years to go on that invention...

    Although my number would be for reloading a rifle that has been shot and consequently fouled. The first round would load a lot faster. I might bump up the rate of fire for trained users...

  3. From my research, the fastest reload time data point for a 17th century rifleman is 60 seconds.