Major Threat Weapons Legacy (5e Variant Rule)
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Major Threat Weapons
This rule is intended to cause firearms to become deadlier and more realistic in how they operate. Although this rule is made with firearms in mind, it can be used for deadlier and more realistic combats with medieval and archaic weapons.
- Renaissance and Mathew Mercer's Firearms
Attacks made with these weapons ignore AC offered by light armor. A creature attacked by these types of weapons is considered to be wearing no armor.
- Modern Firearms
Attacks with these firearms ignore AC offered by any type of medieval armor (suits of armor in the PHB) and AC of creatures with natural armor. A creature attacked by these types of weapons is considered to be wearing no armor.
- Futuristic Firearms
Attacks with these firearms ignore AC offered by any type of armor and from Ballistic Protection and AC of creatures with natural armor. A creature attacked by these types of weapons is considered to be wearing no armor.
Whenever a creature takes damage from a firearm, it loses 1 hit dice and must succeed on a Constitution saving throw against a DC equal to the damage taken, or suffer 1 level of exhaustion. Critical hits cause the creature to lose 2 hit dice and suffer 2 levels of exhaustion on a failed save.
If the creature has no hit dice after being hit by a firearm, it suffers level of exhaustion equal to the amount of hit dice it would lose.
In addition, a critical hit with a firearm have the potential of being even deadlier. If the creature roll a 5 or lower on a saving throw against a critical hit from a firearm, the creature is reduced to 0 hit points.
Lethal Wounds: Ballistic Endurance
To avoid rolling one to many checks and stalling the fight, a character can have a new score called Ballistic Endurance. The character's Ballistic Endurance equals the maximum number possible on its hit die + its Constitution modifier + its proficiency bonus (if the target is proficient in Constitution saving throws).
For example, a 1st-level fighter with a Constitution score of 15 (+2) has a Ballistic Endurance of 10 (maximum number possible on a d10) + 2 (proficiency in Constitution saves) + 2 (Constitution modifier of 15) = 14.
So, if this fighter takes damage equal to 13 or lower from a firearm, it loses one hit die. If it takes damage equal to 14 or higher, it loses 1 hit die and suffer 1 level of exhaustion on a failed save.
Using the Lethal Wounds system also can allow the use of protection other than armor and AC. Without flavoring or enter in details, here are three types of ballistic protection.
Ballistic protection is considered armor, but can only be bypassed by futuristic weapons. In addition, a creature wearing Ballistic Protection is automatically stabilized after being reduced to 0 hit points by an attack with a firearm.
- Light Vest
A light vest is a suit of light armor, that grants an AC equal to 12 + Dexterity modifier (for light vests).
The user has a bonus of + 2 to your Ballistic Endurance and to your Constitution saving throws against Lethal Wounds.
- Medium Vest
A medium vest is a suit of medium armor, that grants an AC of 12 + Dexterity modifier (maximum +2).
The user has a bonus of + 5 to your Ballistic Endurance and to your Constitution saving throws against Lethal Wounds.
- Heavy Vest
A heavy vest is a suit of heavy armor, that grants an AC of 12.
The user has a bonus of + 8 to your Ballistic Endurance and to your Constitution saving throws against Lethal Wounds. You also don't lose hit die when hit by a firearm while wearing a heavy vest, unless the attack is a critical.
In addition, you have disadvantage on Dexterity (Stealth) checks while using a heavy vest.