I'm already currently working on a basic framework for an Injuries system, but once I get that in place, I have a few ideas for where I might take it.

Player Conditions

Similar to potion effects, but cannot be cured through milk, and exclusively effects players
Catch-all for things like injuries and diseases
May require special conditions to treat/cure, or may simply go away over time
Also has an API for developers to implement their own conditions

Display UI

Conditions could be displayed underneath the player's inventory space,
Condition Icons displayed in pure black and white, with with red sometimes taking place of the white to indicate dangerous/fatal conditions
If there are too many conditions to be displayed in one row, conditions could be scrolled through using the scroll wheel
When a player initially gains a condition, an icon is displayed in the bottom right indicating the condition that was gained

New Items

Plants/crops

A new crop, called herbs, can be used to mitigate or treat a variety of ailments
There are different kinds of herbs, denoted primarily by their colors and shapes
- Green Herbs:
- The most common form of herb, can be found in forests and plains biomes
- General purpose treatment for things like minor illnesses
- Red Herbs:
- Found in tropical biomes, such as jungles and savannas
- Yellow Herbs:
- Found in hot regions, like deserts and badlands
- Blue Herbs:
- Found in cold regions, like tundras and taigas
- Purple Herbs:
- Found only underground, growing near water source blocks
- Golden Herbs:
- Not found naturally, unable to be eaten
- Crafted by surrounding any herb with 8 gold ingots
- Used to brew a potion of immunity, which prevents many diseases

Foods and Drinks

Herbal Tea
- Crafted with a bucket of milk, 3 empty bottles, and any herb
- If Farmer's Delight is installed, it can also be made in a cooking pot
- Mainly just used to treat insomnia and ender sickness
Herbal Salad
- Crafted with a bowl and one of each herb type
- Decent food item
Salve
- Just used to treat burn injuries.

Ideas/Brainstorming

Note that none of these have a 100% chance of being implemented in the future-- I'm mainly just spitballing here.

Broken Legs

When a player takes more than 4 hearts (8 hitpoints) of fall damage (configurable), their legs will be broken
Movement speed is hindered slightly, and sprinting is disabled
The time it takes to heal a broken leg depends on the damage taken from the initial fall
- Taking the minimum amount of fall damage to gain this condition will require 5 ingame days to heal
- Taking 9.5 hearts of fall damage (the maximum damage a player can take without dying w/o any max health increases) will require 20 in-game days to heal
The effects of broken legs can be mitigated by crafting a splint and equipping it.
- The splint will significantly reduce the amount of time required for a bone to heal, and reenable sprinting, and sleeping with it on will completely clear the broken leg effect
- However, taking any fall damage with the splint equipped will break the splint and cause healing to return to its normal rate

Zombification

Eating rotten flesh has a small chance to infect the player with zombification, which is a multi-staged disease
Can be configured so that the player has a chance to be infected when being attacked by a zombie (disabled by default)
Stage 1 - Incubation Period (Lasts 2 - 3 in-game days):
- Early stages show no major symptoms, however players' hunger will go down slightly more quickly than usual
- Occasionally the player will be affected by weakness, which means that if you're lucky enough to have a golden apple at this point, you can cure the disease right off the bat.
- You can also cure the disease in this stage with purple herbs. (Only in this stage, however)
Stage 2 - Early Zombification (Lasts 4 - 6 in-game days):
- Randomly, the message "Your yearning for flesh increases..." will appear above your hotbar, causing your exhaustion to go up significantly
- Infection can be decreased by eating rotten flesh
Stage 3 - Mid Zombification (Lasts 14 - 21 in-game days):
- The "yearning for flesh" message will no longer appear, and the random weakness effect will no longur occur.
- The screen will gain a very faint "veiny" overlay
Stage 4 - Late Zombification (Lasts 10 - 14 in-game days):
- Iron golems will attack the player on sight
- Villagers will run away from the player and will not be able to be traded with
Stage 5 - Terminal (Lasts 3 - 4 in-game days):
- At this point, the player is more or less screwed unless they have a cure on hand
- The player can roll back to stage 4 by eating enough rotten flesh
- The player will be set on fire from standing out in the sun
Stage 6 - Death (Lasts until death):
- The player will take damage continuously until they die, with the damage taken increasing over time
- The zombification overlay will be at maximum intensity, making it much more difficult to see
Upon death, the player will still drop almost all of their items, however, a zombie will appear at their death position, equipped with the same armor and same weapons the player had at the time of their death.
- This zombie will have the same skin that the player does, but tinted green
At any point in the disease's progression, the player can be cured by eating a golden apple while afflicted with weakness

Malnourishment

Basically what happens if your hunger remains too low for too long.
When your hunger is below 3 haunches for more than a day or so, players will begin to randomly gain the nausea effect, alongside an indefinite mining fatigue debuff.
Can simply be cured by restoring your hunger back to a full 10 haunches.

Food Poisoning

Eating raw foods (aside from fish) has a random chance to give the player food poisoning.
If the player has food poisoning, attempting to eat other types of food will have a chance to cause the player to vomit-- or if vomit is disabled, will simply cause them to gag and freeze for a moment.
Vomiting causes the player to lose a significant amount of hunger or saturation
Can be cured using green herbs, or by simply waiting out the timer.

Wounded/Bleeding

Attacks from swords and other weapons have a chance to inflict bleeding on a player
This can be prevented by equipping armor
Causes the player to temporarily be unable to recover health from full hunger
Bleeding can be treated by using bandages, which are crafted by arranging string in a 2x3 square on a crafting grid

Leisons

A much more severe form of Bleeding that's caused by attacks from Wither Skeletons
Leisons allow zombies to infect the player on attack, even if the config option for zombies being able to infect players on attack is disabled (though this can also be disabled in and of itself)
Otherwise, pretty much the same as the Bleeding effect and treated in much the same fashion.
Mutually exclusive from Wounded

Burn Injuries

Burn Injuries are acquired from, you guessed it, fire damage
Being on fire for more than 3 seconds will give you this condition
Increases damage from all sources until treated with Red Herbs, or until enough time has passed
Can be treated using Salve, which can be created by crafting together red herbs, green herbs, and a bowl

Ender Sickness

Caused by standing near an enderman for too long, or angering an enderman by looking at them
The player will sometimes recieve nausea, and occasionally vomit for no particular reason.
Hallucinations are also a symptom, displaying mobs and particle effects that are visible only to the player with the condition
Treated using herbal tea

Insomnia

Occasionally inflicted by Phantoms and Strays
Causes the player to be unable to sleep until it is past midnight
Also causes hallucinations if it has gone on for long enough
Can be treated using herbal tea

anIceyGirl / SurvivalOverhaul

Injuries/Conditions System #39