Guns in the Realms

So it turns out that guns are a thing in the Forgotten Realms. They're rare, expensive, unreliable, often inaccurate, and effectively single-use, but can have devastating effects if landed properly.
A gun in the Forgotten Realms is a relatively simple machine. Smokepowder, a magical/alchemical substance that explodes with great force when exposed to flames or sparks, is stuffed into the back of a strengthened iron tube (called a barrel) that is mostly sealed on one end. In front of the smokepowder is stuffed a small lead or iron ball that is slightly smaller than the inside of tube itself.
The open end of the tube is pointed at a target and a mechanism is activated to deliver a spark or flame to a small hole in the sealed end of the tube. The smokepowder explodes and the force of the explosion hurls the ball at incredible speed toward the target .
Most guns in the Forgotten Realms are of the "wheel lock" variety -- when a spring that is wound before every shot is released by a trigger, it causes a roughened steel wheel to grind against pyrite, delivering sparks to the ignition hole of the barrel. Some rare types of guns may use magic to deliver heat to the ignition hole, such as through the use of an embedded fire elemental.

Rules for Guns

• Guns require a special type of two-part ammunition, the projectile fired and the propulsive force. Each type of gun uses a different type of projectile, specifically a lead or iron ball sized to the gun type. Pistol balls are smallest, being about half an inch wide, muskets slightly larger than pistols, and cannons fire 6-inch diameter iron balls.
• Guns use Smokepowder as a propulsive force, which is consumed by the shot and cannot be recovered.
• Although some guns can be fired one-handed, reloading a gun requires two hands.
• Gun projectile ammunition can be modified in the same way arrows and bolts can; poison or enchantments can be added to increase their effective damage or deliver other effects.
• Guns only ever deal lethal force. If you reduce your target to 0 hp with an attack from a gun, the target is killed, although death saving throw rules still apply.
• Pistols and muskets are unreliable and can be dangerous to the wielder. If the wielder of a pistol rolls a natural 1 or 2 on an attack roll, or if the wielder of a musket rolls a natural 1 on an attack roll, the gun misfires.
  • When a gun misfires, the attack automatically fails and a backlash explosion occurs. The wielder suffers 2 (1d4) fire damage and 2 (1d4) thunder damage from the blast, and is blinded and stunned for 3 rounds.
  • A DC 15 Dexterity saving throw can avoid the damage and conditions. At the end of their turn each round the wielder may make a DC 12 Constitution saving throw to shake off the blindness and stunning.
  • A gun that has misfired must be repaired before it can be fired again, a process that takes 1 hour.

Smokepowder

Wondrous item, uncommon
Smokepowder is a magical explosive chiefly used to propel a bullet out of the barrel of a firearm. It is stored in airtight wooden kegs or tiny, waterproof leather packets. A packet contains enough smokepowder for five shots, and a small keg holds enough smokepowder for five hundred shots with a gun or 100 shots with a cannon.
If smokepowder is set on fire, dropped, or otherwise handled roughly, it explodes and deals fire damage to each creature or object within 20 feet of it: ld6 for a packet, 9d6 for a keg. A successful DC 12 Dexterity saving throw halves the damage.
Casting dispel magic on smokepowder renders it permanently inert.
Smokepowder is often considered illegal in large cities, and costs double if purchased on a black market in such cities. Smokepowder is illegal in Waterdeep, but ammunition is not.

Equipment

Item	Cost	Damage	Weight	Properties
Martial	Weapons
Pistol	1250 gp	1d12 P	3 lb.	ammunition (20/100), long-loading (2), critical (1), critical-damage (1), light
Musket	2500 gp	1d12 P	12 lb.	ammunition (80/200), two-handed, long-loading (3), critical (2), critical-damage (2)
Cannon	12,000 gp	4d12 B	2000 lb.	ammunition (600/2000), long-loading (10), critical (3), critical-damage (3)
Smokepowder
Keg	500 gp		30 lb.	500 shots by gun, 100 shots by cannon
Packet	10 gp		1 lb.	watertight leather packet with smokepowder for 5 shots by gun
Cartridge	15 gp		1 lb.	watertight leather packet with 5 paper envelopes, each containing a ball, wadding, and enough smokepowder for one shot.
Ammunition
Ball, gun	25 cp		1 oz.	Also sold 1gp for 5
Ball, cannon	2 gp		2 lb.

New Weapon Properties

light
When you take the Attack action and attack with a light weapon that you're holding in one hand, you can use a bonus action to attack with a different light weapon that you're holding in the other hand. You don't add your ability modifier to the damage of the bonus attack, unless that modifier is negative.
long-loading
A ranged weapon that has the long-loading property functions as if it has the loading property, but it takes even longer to fully load the weapon. The time required is listed as a number of actions that must be taken to load the weapon. These actions need not be made consecutively, meaning that additional actions can be taken in between, but all actions must be spent before the weapon can be fired again. Additionally, the actions can be spent by any number of people; for example, a crew of three manning a cannon can each spend their action loading the cannon.
The number of actions necessary to complete the load is listed in parenthesis after the property; for example, a weapon with the long-loading (2) property would require that the wielder spend two actions in combat before the weapon can be fired again.
critical
A weapon with the critical property increases the critical range for the character using that weapon by the number specified in parenthesis. For example, when a character who normally scores a critical hit on a natural 20 roll uses a weapon with the critical (2) property, they score a critical hit on a roll of 18, 19, or 20. If a character has class options or feats that cause them to score a critical hit on a 19-20 uses a weapon with the critical (2) property, they score a critical hit on a roll of 17, 18, 19, or 20.
critical-damage
A weapon with the critical-damage property increases the number of times extra damage dice are rolled for a critical hit by the number specified in parenthesis. Normally a critical hit doubles (x2) the number of damage dice rolled, so for a weapon that normally does 2d4 damage, 4d4 is rolled for critical damage. A weapon that has the critical-damage (2) property increases the critical hit multiplier by two, from x2 to x4. So for a weapon that does 2d4 damage with the critical-damage (2) property, 8d4 is rolled for critical damage.
The number of dice rolled on a critical are determined before other abilities that increase the damage dice on critical (such as Brutal Critical) are applied.

New Feats

Gunslinger

Thanks to extensive practice with guns, you gain the following benefits:

• You are proficient with guns even if you are not proficient with Martial weapons
• You never suffer misfires when wielding a gun
• You can draw a holstered or braced gun as a bonus action if you have already interacted with an object during your movement
• You reduce the long-loading property of any guns (not cannons) that you wield by 1. If long-loading property becomes zero, treat the gun as having only the loading property.
• Being within 5 feet of a hostile creature does not impose disadvantage on your attack rolls.

You may take the Gunslinger feat multiple times. Each time you do, you reduce the long-loading property of guns you wield by 1.

Expert Crew

Thanks to extensive training, you are better at crewing a cannon. When you spend an action reloading a cannon, you spend a second action as well.
You may take this feat multiple times. Each time you do, you spend an extra action when you spend your action reloading a cannon.