You could add a bunch of homebrew mechanics to D&D. Or, you can do what I did and switch to a system that incorporates that kind of granularity from the start. GURPS has tons of rules for these kinds of injuries.

I wrote a blog post about how Lingering Injuries in the DMG kind of sucks, and proposed better rules:

---

In the Dungeon Master's Guide (2014), there is a section in chapter 9 under the section titled “Lingering Injuries” that applied when a character took a critical hit, dropped to zero hitpoints, or fails a death saving throw by 5 or more. In one of the campaigns I ran, our playgroup wanted a slightly harsher ruleset, but we found the lingering injuries as written to not be particularly fun. We found it to be too frequent; player characters would often end up with many lingering injuries ‒ too severe; player characters would end up with debilitating injuries and it wouldn't be fun to play then ‒ and not applicable to the kind of damage received; how could a character lose an arm after breathing a toxic gas?

So, I present reworked rules for lingering injuries that are more fun and make more sense.

Circumstances for sustaining a Lingering Injury

• When a character is dropped to 0 hit points by a critical hit
• When a character is stabilized or healed after failing two death saving throws
• When a character is revived after dying

We found these conditions to be sufficiently uncommon such that lingering injuries were rare. When a character sustains a lingering injury, roll on one of the following tables applicable to the kind of damage sustained. The tables are arranged such that injuries get worse the lower you roll. Players may use their inspiration, if they have any, to reduce the chances of receiving a severe injury.

Physical Damage

This table can be rolled on when physical damage such as Bludgeoning, Piercing, Slashing, or Force causes a lingering injury.

d20	Injury
1	Lose an appendage.
2	Break an appendage.
3-4	Limp.
5-6	Internal Injury
7-9	Broken Rib
10-12	Horrible Scar
13-15	Festering Wound
16-20	Minor Scar

Lose an appendage

Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a cane or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Break an appendage

Roll on the appendages table. You suffer the same negative effects as losing an appendage, except the injury heals if you receive magical healing such as the Greater Restoration spell or spend two tendays doing nothing but resting.

Limp

Your speed on foot is reduced by 5 feet. You must make a DC 10 Dexterity saving throw after using the Dash action or fall prone. The limp heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Internal Injury

Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Broken Rib

This has the same effect as an internal injury, except the Constitution saving throw DC is 10 instead of 15.

Horrible Scar

You are disfigured to the extent that the wound cannot easily be concealed. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the scar.

Festering Wound

Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the wound persists. If your hit point maximum is reduced to 0 this way, you die. The wound heals if you receive magical healing such as Lesser Restoration. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Scar

A minor scar has no adverse effect beyond cosmetic. Magical healing of 6th level or greater, such as Heal and Regenerate removes the scar.

Heat Damage

This table can be rolled on when heat damage such as Fire, Radiant, or Lightning causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Burns.
4-6	Moderate Burns
7-9	Minor Burns
10-12	Temporary Blindness
13-15	Dehydration
16-20	Singed Hair

Lose an appendage

Your burns are so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Burns

You suffer severe burns across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Burns

You suffer moderate burns across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Burns

You suffer minor burns to some of your body. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. The burns heal completely after a tenday.

Temporary Blindness

The heat damage you received has caused temporary blindness. Until healed, you suffer the blinded condition. Magical healing such as Lesser Restoration heals the blindness. The blindness heals completely after a tenday.

Dehydration

The heat damage has caused you to become dehydrated. Make a DC 10 Constitution saving throw. On a failure, you suffer a level of exhaustion. Repeat this saving throw each day at dawn until you succeed. You have advantage on subsequent saving throws if you are able to consume a full days worth of water in the 24 hours preceding the saving throw.

Singed Hair

The heat has caused your hair (if you have any) to become singed. Roll a d20. On a 10 or greater only some of your hair has been singed. On a 9 or lower all of your hair has been singed off.

Cold and Necrotic Damage

This table can be rolled on when cold or necrotic damage causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Frostbite or Necrosis.
4-6	Moderate Frostbite or Necrosis
7-9	Minor Frostbite or Necrosis
10-15	Numbness
15-20	Blue Lips

Lose an appendage

Your frostbite/necrosis is so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Frostbite or Necrosis

You suffer frostbite/necrosis across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Frostbite or Necrosis

You suffer moderate frostbite/necrosis across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Frostbite or Necrosis

You suffer minor frostbite/necrosis to some of your body. While the burns persist, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. The injury heals completely after a tenday.

Numbness

The cold or necrotic damage has caused numbness. You have disadvantage on sleight of hand checks and on initiative rolls for the next hour. Magical healing such as Lesser Restoration removes this effect.

Blue Lips

The lack of blood circulation causes your lips to turn blue for the next hour.

Thunder Damage

This table can be rolled on when thunder damage causes a lingering injury.

d20	Injury
1	Deafness.
2-3	Internal Injury.
4-6	Concussion
7-9	Temporary Deafness
10-15	Ringing Headache
15-20	Disoriented

Deafness

The extreme sound has caused you to go permanently deaf. Unless healed, you permanently gain the deafened condition. Magical healing such as Greater Restoration can cure this injury.

Internal Injury

The shockwave caused by the thunder damage has caused an internal injury. Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Concussion

The shockwave has caused a concussion. While concussed, you have disadvantage on all Intelligence ability checks, attack rolls, and saving throws. The concussion heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Temporary Deafness

The thunder damage has caused temporary deafness. For the next 1d4 hours you gain the deafened condition. You lose this condition if you receive magical healing such as the Lesser Restoration spell.

Ringing Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Disoriented

The thunder damage has caused disorientation. For the next 10 minutes you have disadvantage on all ability checks to locate your way or read maps.

Acid Damage

This table can be rolled on when acid damage causes a lingering injury.

d20	Injury
1	Blinded.
2-3	Corroded Arms.
4-6	Corroded Legs
7-9	Corroded Armour
10-15	Disfiguring Burns
15-20	Smelly

Blinded

The acid damage has corroded your eyes. Unless healed, you permanently gain the blinded condition. You lose this condition if you receive magical healing such as the Greater Restoration spell.

Corroded Arms

Your arms have been badly damaged by the corroding effects of the acid damage. Until healed, you have disadvantage on ability checks and attack rolls relying on the use of your arms, including spells cast that have somatic components, and attack rolls made with weapons such as swords or bows. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Legs

Your legs have been badly damaged by the corroding effects of the acid damage. Until healed, your speed is reduced by 5 feet, and after taking the dash action you must succeed on a DC 10 Dexterity saving throw or fall prone. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Armour

If wearing armour while you took the acid damage it has been corroded. The benefit you receive to your armour class by wearing this armour is reduced by 1. The armour may be repaired at a blacksmith for 50% of its original purchase value.

Disfiguring Burns

Your face has been disfigured by the corrosion of the acid. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the disfiguration.

Smelly

The powerful scent of acid remains on your body for 1d4 hours. Any creating attempting to detect you relying on scent has advantage on any ability checks made to do so.

Psychic Damage

This table can be rolled on when Psychic damage causes a lingering injury.

d20	Injury
1	Long Term Madness.
2-3	Recurring Nightmares.
4-6	Mental Lethargy
7-9	Visual Hallucinations
1-2	Short Term Madness
10-15	Paranoia
15-20	Headache
1-2	Mirthfulness

Madness

Roll for a Long Term Madness effect in the Dungeons Masters Guide in chapter 8.

Recurring Nightmares

Whenever you take a long rest roll a d20. On a 10 or above, you suffer no ill effects. On a 9 or below, you suffer a nightmare relating to the cause of your lingering injury and do not benefit from the effects of the long rest. As part of your restlessness, you gain a level of exhaustion when you wake. The recurring nightmares are cured by magical healing such as the Greater Restoration spell, or by succeeding on your check three times.

Mental Lethargy

For the next 1d4 days, you have disadvantage on Constitution saving throws made to maintain concentration on spells. This injury is cured by magical healing such as the Lesser Restoration spell.

Visual Hallucinations**

For the next 1d4 days, you have disadvantage on Wisdom (Perception) checks made using your sight, as intrusive hallucinations make it difficult to concentrate. This injury is cured by magical healing such as the Lesser Restoration spell.

Short Term Madness

Roll for a Short Term Madness effect in the Dungeons Masters Guide in chapter 8.

Paranoia

For the next 1d4 days, you have disadvantage on Wisdom (Insight) checks thanks to a mistrust caused by the psychic damage. This injury is cured by magical healing such as the Lesser Restoration spell.

Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Mirthfulness

For the next 1d4 hours you find everything funnier than it ought to be. You often burst into peals of uncontrollable laughter. You have disadvantage on stealth checks made within earshot of enemies. This injury is cured with magical healing such as the Lesser Restoration spell.

Appendix

Appendage Table

Roll on this table to determine the appendage affected by a lingering injury. If the affected character has other appendages, such as a tail or wings, you may modify the table to include those.

d20	Appendage
1-5	Right Hand
6-10	Left Hand
11-15	Right Foot
16-20	Left Foot

I wrote a blog post about how Lingering Injuries in the DMG kind of sucks, and proposed better rules:

---

In the Dungeon Master's Guide (2014), there is a section in chapter 9 under the section titled “Lingering Injuries” that applied when a character took a critical hit, dropped to zero hitpoints, or fails a death saving throw by 5 or more. In one of the campaigns I ran, our playgroup wanted a slightly harsher ruleset, but we found the lingering injuries as written to not be particularly fun. We found it to be too frequent; player characters would often end up with many lingering injuries ‒ too severe; player characters would end up with debilitating injuries and it wouldn't be fun to play then ‒ and not applicable to the kind of damage received; how could a character lose an arm after breathing a toxic gas?

So, I present reworked rules for lingering injuries that are more fun and make more sense.

Circumstances for sustaining a Lingering Injury

• When a character is dropped to 0 hit points by a critical hit
• When a character is stabilized or healed after failing two death saving throws
• When a character is revived after dying

We found these conditions to be sufficiently uncommon such that lingering injuries were rare. When a character sustains a lingering injury, roll on one of the following tables applicable to the kind of damage sustained. The tables are arranged such that injuries get worse the lower you roll. Players may use their inspiration, if they have any, to reduce the chances of receiving a severe injury.

Physical Damage

This table can be rolled on when physical damage such as Bludgeoning, Piercing, Slashing, or Force causes a lingering injury.

d20	Injury
1	Lose an appendage.
2	Break an appendage.
3-4	Limp.
5-6	Internal Injury
7-9	Broken Rib
10-12	Horrible Scar
13-15	Festering Wound
16-20	Minor Scar

Lose an appendage

Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a cane or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Break an appendage

Roll on the appendages table. You suffer the same negative effects as losing an appendage, except the injury heals if you receive magical healing such as the Greater Restoration spell or spend two tendays doing nothing but resting.

Limp

Your speed on foot is reduced by 5 feet. You must make a DC 10 Dexterity saving throw after using the Dash action or fall prone. The limp heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Internal Injury

Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Broken Rib

This has the same effect as an internal injury, except the Constitution saving throw DC is 10 instead of 15.

Horrible Scar

You are disfigured to the extent that the wound cannot easily be concealed. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the scar.

Festering Wound

Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the wound persists. If your hit point maximum is reduced to 0 this way, you die. The wound heals if you receive magical healing such as Lesser Restoration. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Scar

A minor scar has no adverse effect beyond cosmetic. Magical healing of 6th level or greater, such as Heal and Regenerate removes the scar.

Heat Damage

This table can be rolled on when heat damage such as Fire, Radiant, or Lightning causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Burns.
4-6	Moderate Burns
7-9	Minor Burns
10-12	Temporary Blindness
13-15	Dehydration
16-20	Singed Hair

Lose an appendage

Your burns are so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Burns

You suffer severe burns across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Burns

You suffer moderate burns across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Burns

You suffer minor burns to some of your body. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. The burns heal completely after a tenday.

Temporary Blindness

The heat damage you received has caused temporary blindness. Until healed, you suffer the blinded condition. Magical healing such as Lesser Restoration heals the blindness. The blindness heals completely after a tenday.

Dehydration

The heat damage has caused you to become dehydrated. Make a DC 10 Constitution saving throw. On a failure, you suffer a level of exhaustion. Repeat this saving throw each day at dawn until you succeed. You have advantage on subsequent saving throws if you are able to consume a full days worth of water in the 24 hours preceding the saving throw.

Singed Hair

The heat has caused your hair (if you have any) to become singed. Roll a d20. On a 10 or greater only some of your hair has been singed. On a 9 or lower all of your hair has been singed off.

Cold and Necrotic Damage

This table can be rolled on when cold or necrotic damage causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Frostbite or Necrosis.
4-6	Moderate Frostbite or Necrosis
7-9	Minor Frostbite or Necrosis
10-15	Numbness
15-20	Blue Lips

Lose an appendage

Your frostbite/necrosis is so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Frostbite or Necrosis

You suffer frostbite/necrosis across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Frostbite or Necrosis

You suffer moderate frostbite/necrosis across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Frostbite or Necrosis

You suffer minor frostbite/necrosis to some of your body. While the burns persist, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. The injury heals completely after a tenday.

Numbness

The cold or necrotic damage has caused numbness. You have disadvantage on sleight of hand checks and on initiative rolls for the next hour. Magical healing such as Lesser Restoration removes this effect.

Blue Lips

The lack of blood circulation causes your lips to turn blue for the next hour.

Thunder Damage

This table can be rolled on when thunder damage causes a lingering injury.

d20	Injury
1	Deafness.
2-3	Internal Injury.
4-6	Concussion
7-9	Temporary Deafness
10-15	Ringing Headache
15-20	Disoriented

Deafness

The extreme sound has caused you to go permanently deaf. Unless healed, you permanently gain the deafened condition. Magical healing such as Greater Restoration can cure this injury.

Internal Injury

The shockwave caused by the thunder damage has caused an internal injury. Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Concussion

The shockwave has caused a concussion. While concussed, you have disadvantage on all Intelligence ability checks, attack rolls, and saving throws. The concussion heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Temporary Deafness

The thunder damage has caused temporary deafness. For the next 1d4 hours you gain the deafened condition. You lose this condition if you receive magical healing such as the Lesser Restoration spell.

Ringing Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Disoriented

The thunder damage has caused disorientation. For the next 10 minutes you have disadvantage on all ability checks to locate your way or read maps.

Acid Damage

This table can be rolled on when acid damage causes a lingering injury.

d20	Injury
1	Blinded.
2-3	Corroded Arms.
4-6	Corroded Legs
7-9	Corroded Armour
10-15	Disfiguring Burns
15-20	Smelly

Blinded

The acid damage has corroded your eyes. Unless healed, you permanently gain the blinded condition. You lose this condition if you receive magical healing such as the Greater Restoration spell.

Corroded Arms

Your arms have been badly damaged by the corroding effects of the acid damage. Until healed, you have disadvantage on ability checks and attack rolls relying on the use of your arms, including spells cast that have somatic components, and attack rolls made with weapons such as swords or bows. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Legs

Your legs have been badly damaged by the corroding effects of the acid damage. Until healed, your speed is reduced by 5 feet, and after taking the dash action you must succeed on a DC 10 Dexterity saving throw or fall prone. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Armour

If wearing armour while you took the acid damage it has been corroded. The benefit you receive to your armour class by wearing this armour is reduced by 1. The armour may be repaired at a blacksmith for 50% of its original purchase value.

Disfiguring Burns

Your face has been disfigured by the corrosion of the acid. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the disfiguration.

Smelly

The powerful scent of acid remains on your body for 1d4 hours. Any creating attempting to detect you relying on scent has advantage on any ability checks made to do so.

Psychic Damage

This table can be rolled on when Psychic damage causes a lingering injury.

d20	Injury
1	Long Term Madness.
2-3	Recurring Nightmares.
4-6	Mental Lethargy
7-9	Visual Hallucinations
1-2	Short Term Madness
10-15	Paranoia
15-20	Headache
1-2	Mirthfulness

Madness

Roll for a Long Term Madness effect in the Dungeons Masters Guide in chapter 8.

Recurring Nightmares

Whenever you take a long rest roll a d20. On a 10 or above, you suffer no ill effects. On a 9 or below, you suffer a nightmare relating to the cause of your lingering injury and do not benefit from the effects of the long rest. As part of your restlessness, you gain a level of exhaustion when you wake. The recurring nightmares are cured by magical healing such as the Greater Restoration spell, or by succeeding on your check three times.

Mental Lethargy

For the next 1d4 days, you have disadvantage on Constitution saving throws made to maintain concentration on spells. This injury is cured by magical healing such as the Lesser Restoration spell.

Visual Hallucinations**

For the next 1d4 days, you have disadvantage on Wisdom (Perception) checks made using your sight, as intrusive hallucinations make it difficult to concentrate. This injury is cured by magical healing such as the Lesser Restoration spell.

Short Term Madness

Roll for a Short Term Madness effect in the Dungeons Masters Guide in chapter 8.

Paranoia

For the next 1d4 days, you have disadvantage on Wisdom (Insight) checks thanks to a mistrust caused by the psychic damage. This injury is cured by magical healing such as the Lesser Restoration spell.

Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Mirthfulness

For the next 1d4 hours you find everything funnier than it ought to be. You often burst into peals of uncontrollable laughter. You have disadvantage on stealth checks made within earshot of enemies. This injury is cured with magical healing such as the Lesser Restoration spell.

Appendix

Appendage Table

Roll on this table to determine the appendage affected by a lingering injury. If the affected character has other appendages, such as a tail or wings, you may modify the table to include those.

d20	Appendage
1-5	Right Hand
6-10	Left Hand
11-15	Right Foot
16-20	Left Foot

GURPS is neat in its own way, but this is just about someone fixing one specific mechanic in D&D. Provided they’re ok with the rest of the rules, switching systems wholesale (especially to something as famously fiddly as GURPS) just because of how they handle injuries would be absurd.

You could add a bunch of homebrew mechanics to D&D. Or, you can do what I did and switch to a system that incorporates that kind of granularity from the start. GURPS has tons of rules for these kinds of injuries.

You could add a bunch of homebrew mechanics to D&D. Or, you can do what I did and switch to a system that incorporates that kind of granularity from the start. GURPS has tons of rules for these kinds of injuries.

I wrote a blog post about how Lingering Injuries in the DMG kind of sucks, and proposed better rules:

---

In the Dungeon Master's Guide (2014), there is a section in chapter 9 under the section titled “Lingering Injuries” that applied when a character took a critical hit, dropped to zero hitpoints, or fails a death saving throw by 5 or more. In one of the campaigns I ran, our playgroup wanted a slightly harsher ruleset, but we found the lingering injuries as written to not be particularly fun. We found it to be too frequent; player characters would often end up with many lingering injuries ‒ too severe; player characters would end up with debilitating injuries and it wouldn't be fun to play then ‒ and not applicable to the kind of damage received; how could a character lose an arm after breathing a toxic gas?

So, I present reworked rules for lingering injuries that are more fun and make more sense.

Circumstances for sustaining a Lingering Injury

• When a character is dropped to 0 hit points by a critical hit
• When a character is stabilized or healed after failing two death saving throws
• When a character is revived after dying

We found these conditions to be sufficiently uncommon such that lingering injuries were rare. When a character sustains a lingering injury, roll on one of the following tables applicable to the kind of damage sustained. The tables are arranged such that injuries get worse the lower you roll. Players may use their inspiration, if they have any, to reduce the chances of receiving a severe injury.

Physical Damage

This table can be rolled on when physical damage such as Bludgeoning, Piercing, Slashing, or Force causes a lingering injury.

d20	Injury
1	Lose an appendage.
2	Break an appendage.
3-4	Limp.
5-6	Internal Injury
7-9	Broken Rib
10-12	Horrible Scar
13-15	Festering Wound
16-20	Minor Scar

Lose an appendage

Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a cane or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Break an appendage

Roll on the appendages table. You suffer the same negative effects as losing an appendage, except the injury heals if you receive magical healing such as the Greater Restoration spell or spend two tendays doing nothing but resting.

Limp

Your speed on foot is reduced by 5 feet. You must make a DC 10 Dexterity saving throw after using the Dash action or fall prone. The limp heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Internal Injury

Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Broken Rib

This has the same effect as an internal injury, except the Constitution saving throw DC is 10 instead of 15.

Horrible Scar

You are disfigured to the extent that the wound cannot easily be concealed. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the scar.

Festering Wound

Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the wound persists. If your hit point maximum is reduced to 0 this way, you die. The wound heals if you receive magical healing such as Lesser Restoration. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Scar

A minor scar has no adverse effect beyond cosmetic. Magical healing of 6th level or greater, such as Heal and Regenerate removes the scar.

Heat Damage

This table can be rolled on when heat damage such as Fire, Radiant, or Lightning causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Burns.
4-6	Moderate Burns
7-9	Minor Burns
10-12	Temporary Blindness
13-15	Dehydration
16-20	Singed Hair

Lose an appendage

Your burns are so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Burns

You suffer severe burns across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Burns

You suffer moderate burns across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Burns

You suffer minor burns to some of your body. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. The burns heal completely after a tenday.

Temporary Blindness

The heat damage you received has caused temporary blindness. Until healed, you suffer the blinded condition. Magical healing such as Lesser Restoration heals the blindness. The blindness heals completely after a tenday.

Dehydration

The heat damage has caused you to become dehydrated. Make a DC 10 Constitution saving throw. On a failure, you suffer a level of exhaustion. Repeat this saving throw each day at dawn until you succeed. You have advantage on subsequent saving throws if you are able to consume a full days worth of water in the 24 hours preceding the saving throw.

Singed Hair

The heat has caused your hair (if you have any) to become singed. Roll a d20. On a 10 or greater only some of your hair has been singed. On a 9 or lower all of your hair has been singed off.

Cold and Necrotic Damage

This table can be rolled on when cold or necrotic damage causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Frostbite or Necrosis.
4-6	Moderate Frostbite or Necrosis
7-9	Minor Frostbite or Necrosis
10-15	Numbness
15-20	Blue Lips

Lose an appendage

Your frostbite/necrosis is so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Frostbite or Necrosis

You suffer frostbite/necrosis across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Frostbite or Necrosis

You suffer moderate frostbite/necrosis across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Frostbite or Necrosis

You suffer minor frostbite/necrosis to some of your body. While the burns persist, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. The injury heals completely after a tenday.

Numbness

The cold or necrotic damage has caused numbness. You have disadvantage on sleight of hand checks and on initiative rolls for the next hour. Magical healing such as Lesser Restoration removes this effect.

Blue Lips

The lack of blood circulation causes your lips to turn blue for the next hour.

Thunder Damage

This table can be rolled on when thunder damage causes a lingering injury.

d20	Injury
1	Deafness.
2-3	Internal Injury.
4-6	Concussion
7-9	Temporary Deafness
10-15	Ringing Headache
15-20	Disoriented

Deafness

The extreme sound has caused you to go permanently deaf. Unless healed, you permanently gain the deafened condition. Magical healing such as Greater Restoration can cure this injury.

Internal Injury

The shockwave caused by the thunder damage has caused an internal injury. Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Concussion

The shockwave has caused a concussion. While concussed, you have disadvantage on all Intelligence ability checks, attack rolls, and saving throws. The concussion heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Temporary Deafness

The thunder damage has caused temporary deafness. For the next 1d4 hours you gain the deafened condition. You lose this condition if you receive magical healing such as the Lesser Restoration spell.

Ringing Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Disoriented

The thunder damage has caused disorientation. For the next 10 minutes you have disadvantage on all ability checks to locate your way or read maps.

Acid Damage

This table can be rolled on when acid damage causes a lingering injury.

d20	Injury
1	Blinded.
2-3	Corroded Arms.
4-6	Corroded Legs
7-9	Corroded Armour
10-15	Disfiguring Burns
15-20	Smelly

Blinded

The acid damage has corroded your eyes. Unless healed, you permanently gain the blinded condition. You lose this condition if you receive magical healing such as the Greater Restoration spell.

Corroded Arms

Your arms have been badly damaged by the corroding effects of the acid damage. Until healed, you have disadvantage on ability checks and attack rolls relying on the use of your arms, including spells cast that have somatic components, and attack rolls made with weapons such as swords or bows. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Legs

Your legs have been badly damaged by the corroding effects of the acid damage. Until healed, your speed is reduced by 5 feet, and after taking the dash action you must succeed on a DC 10 Dexterity saving throw or fall prone. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Armour

If wearing armour while you took the acid damage it has been corroded. The benefit you receive to your armour class by wearing this armour is reduced by 1. The armour may be repaired at a blacksmith for 50% of its original purchase value.

Disfiguring Burns

Your face has been disfigured by the corrosion of the acid. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the disfiguration.

Smelly

The powerful scent of acid remains on your body for 1d4 hours. Any creating attempting to detect you relying on scent has advantage on any ability checks made to do so.

Psychic Damage

This table can be rolled on when Psychic damage causes a lingering injury.

d20	Injury
1	Long Term Madness.
2-3	Recurring Nightmares.
4-6	Mental Lethargy
7-9	Visual Hallucinations
1-2	Short Term Madness
10-15	Paranoia
15-20	Headache
1-2	Mirthfulness

Madness

Roll for a Long Term Madness effect in the Dungeons Masters Guide in chapter 8.

Recurring Nightmares

Whenever you take a long rest roll a d20. On a 10 or above, you suffer no ill effects. On a 9 or below, you suffer a nightmare relating to the cause of your lingering injury and do not benefit from the effects of the long rest. As part of your restlessness, you gain a level of exhaustion when you wake. The recurring nightmares are cured by magical healing such as the Greater Restoration spell, or by succeeding on your check three times.

Mental Lethargy

For the next 1d4 days, you have disadvantage on Constitution saving throws made to maintain concentration on spells. This injury is cured by magical healing such as the Lesser Restoration spell.

Visual Hallucinations**

For the next 1d4 days, you have disadvantage on Wisdom (Perception) checks made using your sight, as intrusive hallucinations make it difficult to concentrate. This injury is cured by magical healing such as the Lesser Restoration spell.

Short Term Madness

Roll for a Short Term Madness effect in the Dungeons Masters Guide in chapter 8.

Paranoia

For the next 1d4 days, you have disadvantage on Wisdom (Insight) checks thanks to a mistrust caused by the psychic damage. This injury is cured by magical healing such as the Lesser Restoration spell.

Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Mirthfulness

For the next 1d4 hours you find everything funnier than it ought to be. You often burst into peals of uncontrollable laughter. You have disadvantage on stealth checks made within earshot of enemies. This injury is cured with magical healing such as the Lesser Restoration spell.

Appendix

Appendage Table

Roll on this table to determine the appendage affected by a lingering injury. If the affected character has other appendages, such as a tail or wings, you may modify the table to include those.

d20	Appendage
1-5	Right Hand
6-10	Left Hand
11-15	Right Foot
16-20	Left Foot

I wrote a blog post about how Lingering Injuries in the DMG kind of sucks, and proposed better rules:

---

In the Dungeon Master's Guide (2014), there is a section in chapter 9 under the section titled “Lingering Injuries” that applied when a character took a critical hit, dropped to zero hitpoints, or fails a death saving throw by 5 or more. In one of the campaigns I ran, our playgroup wanted a slightly harsher ruleset, but we found the lingering injuries as written to not be particularly fun. We found it to be too frequent; player characters would often end up with many lingering injuries ‒ too severe; player characters would end up with debilitating injuries and it wouldn't be fun to play then ‒ and not applicable to the kind of damage received; how could a character lose an arm after breathing a toxic gas?

So, I present reworked rules for lingering injuries that are more fun and make more sense.

Circumstances for sustaining a Lingering Injury

• When a character is dropped to 0 hit points by a critical hit
• When a character is stabilized or healed after failing two death saving throws
• When a character is revived after dying

We found these conditions to be sufficiently uncommon such that lingering injuries were rare. When a character sustains a lingering injury, roll on one of the following tables applicable to the kind of damage sustained. The tables are arranged such that injuries get worse the lower you roll. Players may use their inspiration, if they have any, to reduce the chances of receiving a severe injury.

Physical Damage

This table can be rolled on when physical damage such as Bludgeoning, Piercing, Slashing, or Force causes a lingering injury.

d20	Injury
1	Lose an appendage.
2	Break an appendage.
3-4	Limp.
5-6	Internal Injury
7-9	Broken Rib
10-12	Horrible Scar
13-15	Festering Wound
16-20	Minor Scar

Lose an appendage

Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a cane or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Break an appendage

Roll on the appendages table. You suffer the same negative effects as losing an appendage, except the injury heals if you receive magical healing such as the Greater Restoration spell or spend two tendays doing nothing but resting.

Limp

Your speed on foot is reduced by 5 feet. You must make a DC 10 Dexterity saving throw after using the Dash action or fall prone. The limp heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Internal Injury

Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Broken Rib

This has the same effect as an internal injury, except the Constitution saving throw DC is 10 instead of 15.

Horrible Scar

You are disfigured to the extent that the wound cannot easily be concealed. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the scar.

Festering Wound

Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the wound persists. If your hit point maximum is reduced to 0 this way, you die. The wound heals if you receive magical healing such as Lesser Restoration. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Scar

A minor scar has no adverse effect beyond cosmetic. Magical healing of 6th level or greater, such as Heal and Regenerate removes the scar.

Heat Damage

This table can be rolled on when heat damage such as Fire, Radiant, or Lightning causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Burns.
4-6	Moderate Burns
7-9	Minor Burns
10-12	Temporary Blindness
13-15	Dehydration
16-20	Singed Hair

Lose an appendage

Your burns are so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Burns

You suffer severe burns across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Burns

You suffer moderate burns across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the burns persist. If your hit point maximum is reduced to 0 this way, you die. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Burns

You suffer minor burns to some of your body. While the burns persist, you have vulnerability to fire, lightning, and radiant damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. The burns heal completely after a tenday.

Temporary Blindness

The heat damage you received has caused temporary blindness. Until healed, you suffer the blinded condition. Magical healing such as Lesser Restoration heals the blindness. The blindness heals completely after a tenday.

Dehydration

The heat damage has caused you to become dehydrated. Make a DC 10 Constitution saving throw. On a failure, you suffer a level of exhaustion. Repeat this saving throw each day at dawn until you succeed. You have advantage on subsequent saving throws if you are able to consume a full days worth of water in the 24 hours preceding the saving throw.

Singed Hair

The heat has caused your hair (if you have any) to become singed. Roll a d20. On a 10 or greater only some of your hair has been singed. On a 9 or lower all of your hair has been singed off.

Cold and Necrotic Damage

This table can be rolled on when cold or necrotic damage causes a lingering injury.

d20	Injury
1	Lose an appendage.
2-3	Severe Frostbite or Necrosis.
4-6	Moderate Frostbite or Necrosis
7-9	Minor Frostbite or Necrosis
10-15	Numbness
15-20	Blue Lips

Lose an appendage

Your frostbite/necrosis is so severe that you lose an appendage. Roll on the appendages table. You lose the corresponding appendage. If you have already lost that appendage, then nothing occurs. If you lose an arm you cannot hold anything with two hands and can only hold a single object at a time. If you lose a leg, your speed on foot is halved, and you must use a can or a crutch to move unless you have a peg leg or other prosthesis. You fall prone after using the Dash action. You have disadvantage on dexterity checks made to balance. In both cases, magic such as the Regenerate spell can restore the lost appendage. At the DMs discretion, players may be able to lessen the negative effects over time of losing an appendage as their player character learns to adapt to their altered form.

Severe Frostbite or Necrosis

You suffer frostbite/necrosis across your entire body. Your hit point maximum is reduced by 1d4 and again by 1d4 every hour while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. Alternatively, somebody tending to the wound can make a DC 15 Wisdom (Medicine) check once every hour, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Moderate Frostbite or Necrosis

You suffer moderate frostbite/necrosis across a significant part of your body. Your hit point maximum is reduced by 1d4 and again by 1d4 every day at dawn while the injury persists. If your hit point maximum is reduced to 0 this way, you die. While the injury persists, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the burns. Alternatively, somebody tending to the wound can make a DC 10 Wisdom (Medicine) check once every 24 hours, negating the hit point reduction on a success, and completely healing the wound after three successes. Once the wound is healed in either way, the reduction to your hit point maximum is undone.

Minor Frostbite or Necrosis

You suffer minor frostbite/necrosis to some of your body. While the burns persist, you have vulnerability to cold and necrotic damage. Magical healing of 6th level or greater, such as Heal and Regenerate heals the injury. The injury heals completely after a tenday.

Numbness

The cold or necrotic damage has caused numbness. You have disadvantage on sleight of hand checks and on initiative rolls for the next hour. Magical healing such as Lesser Restoration removes this effect.

Blue Lips

The lack of blood circulation causes your lips to turn blue for the next hour.

Thunder Damage

This table can be rolled on when thunder damage causes a lingering injury.

d20	Injury
1	Deafness.
2-3	Internal Injury.
4-6	Concussion
7-9	Temporary Deafness
10-15	Ringing Headache
15-20	Disoriented

Deafness

The extreme sound has caused you to go permanently deaf. Unless healed, you permanently gain the deafened condition. Magical healing such as Greater Restoration can cure this injury.

Internal Injury

The shockwave caused by the thunder damage has caused an internal injury. Whenever you attempt an action in combat or in other sufficiently high intensity circumstances at the DMs discretion, you must make a DC 15 Constitution saving throw. On a failure, you lose your actions and are unable to make reactions until the start of your next turn. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Concussion

The shockwave has caused a concussion. While concussed, you have disadvantage on all Intelligence ability checks, attack rolls, and saving throws. The concussion heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Temporary Deafness

The thunder damage has caused temporary deafness. For the next 1d4 hours you gain the deafened condition. You lose this condition if you receive magical healing such as the Lesser Restoration spell.

Ringing Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Disoriented

The thunder damage has caused disorientation. For the next 10 minutes you have disadvantage on all ability checks to locate your way or read maps.

Acid Damage

This table can be rolled on when acid damage causes a lingering injury.

d20	Injury
1	Blinded.
2-3	Corroded Arms.
4-6	Corroded Legs
7-9	Corroded Armour
10-15	Disfiguring Burns
15-20	Smelly

Blinded

The acid damage has corroded your eyes. Unless healed, you permanently gain the blinded condition. You lose this condition if you receive magical healing such as the Greater Restoration spell.

Corroded Arms

Your arms have been badly damaged by the corroding effects of the acid damage. Until healed, you have disadvantage on ability checks and attack rolls relying on the use of your arms, including spells cast that have somatic components, and attack rolls made with weapons such as swords or bows. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Legs

Your legs have been badly damaged by the corroding effects of the acid damage. Until healed, your speed is reduced by 5 feet, and after taking the dash action you must succeed on a DC 10 Dexterity saving throw or fall prone. The injury heals if you receive magical healing such as the Lesser Restoration spell, or if you spend a tenday doing nothing but resting.

Corroded Armour

If wearing armour while you took the acid damage it has been corroded. The benefit you receive to your armour class by wearing this armour is reduced by 1. The armour may be repaired at a blacksmith for 50% of its original purchase value.

Disfiguring Burns

Your face has been disfigured by the corrosion of the acid. You have disadvantage on Charisma (Persuasion) checks, and advantage on Charisma (Intimidation) checks. Magical healing of 6th level or higher, such as Heal and Regenerate, removes the disfiguration.

Smelly

The powerful scent of acid remains on your body for 1d4 hours. Any creating attempting to detect you relying on scent has advantage on any ability checks made to do so.

Psychic Damage

This table can be rolled on when Psychic damage causes a lingering injury.

d20	Injury
1	Long Term Madness.
2-3	Recurring Nightmares.
4-6	Mental Lethargy
7-9	Visual Hallucinations
1-2	Short Term Madness
10-15	Paranoia
15-20	Headache
1-2	Mirthfulness

Madness

Roll for a Long Term Madness effect in the Dungeons Masters Guide in chapter 8.

Recurring Nightmares

Whenever you take a long rest roll a d20. On a 10 or above, you suffer no ill effects. On a 9 or below, you suffer a nightmare relating to the cause of your lingering injury and do not benefit from the effects of the long rest. As part of your restlessness, you gain a level of exhaustion when you wake. The recurring nightmares are cured by magical healing such as the Greater Restoration spell, or by succeeding on your check three times.

Mental Lethargy

For the next 1d4 days, you have disadvantage on Constitution saving throws made to maintain concentration on spells. This injury is cured by magical healing such as the Lesser Restoration spell.

Visual Hallucinations**

For the next 1d4 days, you have disadvantage on Wisdom (Perception) checks made using your sight, as intrusive hallucinations make it difficult to concentrate. This injury is cured by magical healing such as the Lesser Restoration spell.

Short Term Madness

Roll for a Short Term Madness effect in the Dungeons Masters Guide in chapter 8.

Paranoia

For the next 1d4 days, you have disadvantage on Wisdom (Insight) checks thanks to a mistrust caused by the psychic damage. This injury is cured by magical healing such as the Lesser Restoration spell.

Headache

For the next 1d4 hours you have disadvantage on Wisdom (Perception) checks made relying on sound. This injury is cured with magical healing such as the Lesser Restoration spell.

Mirthfulness

For the next 1d4 hours you find everything funnier than it ought to be. You often burst into peals of uncontrollable laughter. You have disadvantage on stealth checks made within earshot of enemies. This injury is cured with magical healing such as the Lesser Restoration spell.

Appendix

Appendage Table

Roll on this table to determine the appendage affected by a lingering injury. If the affected character has other appendages, such as a tail or wings, you may modify the table to include those.

d20	Appendage
1-5	Right Hand
6-10	Left Hand
11-15	Right Foot
16-20	Left Foot

I do find it puzzling when people homebrew and tinker and modify D&D 5e to fix all the things they don't like, but they don't want to just change to another system. It's mostly harmless, at least.

The hurdle I see to that is not necessarily changing system myself, but convincing my playgroup to change too. It's hard enough scheduling the group, let alone getting them to learn a new system!