Health Dice a different use of Hit Dice for OSR and 5th edition

Art by Luigi Castellani
from the Spears of the Dawn free art pack

Health Dice
The basic idea behind this article is that Health Dice (HD) are fixed (10+Constitution bonus) and the type of die (d4, d6, d8) is determined by the character class.

Hit Points (HP) are, as before, just based on class and level.

In this system HP will better represent the ability to avoid fatal damage, while HD will represent the capacity of the character to recover HP.
Furthermore HD are recovered slowly and so they will represent the overall status of Health and Stamina of the character.

Number and type of Health Die (HD)
Each character will have HD equal to 10+Constitution bonus (-3 to +3) and the type of dice will be based on their class (in an OSR game we will have: Magic-Users d4, Hybrids d6, Warriors d8).
So a Fighter (d8 HD) with Constitution 13 will have 11d10 HD, a Mage (d4 HD) with Constitution 7 will have 9d4 HD.

HP recovery
As for 5th edition rules you can recover one or more (HD+Con bonus) during a "short rest" (anything from 10 minutes to one hour of rest).

HD recovery
As in 5th edition you will recover half maximum HD for each "long rest" (a full night of sleep) .

Cure Wounds
Cure spells (and  cure spell from wands, scroll and the like, potions and elixirs could make exception) should work in a slightly different manner (specially when this rules are used with the Recharging Spells rules).

Each Cure spell when used on a character will work by instantly giving the effects of a powered up "short rest", a cure spell will consume 1 HD from the receiving character that will recover (1+level of the cure spell)*(HD).

EG: a character with d8 HD will recover 2d8 from a 1st level Cure light Wounds and 5d8 from a 4th level Cure Critical Wounds, while a character with d4 HD will recover 2d4 from a 1st level spell and 5d4 from a 4th level spell.

Wounds, Fatigue, disease and other ailments
Optionally such rules can add a simple way of tracking various long term ailments of the character.

The recovery of some or all the HD can be blocked by specific conditions that can be removed by specific remedies.

Wounds
Wounds are long term damage that the character will get when he goes to 0 HP, at 0 HP a character is Knocked Out and is wounded or dead.

The severity of wounds can be rolled with various systems. The use of a Death and Dismemberment table is a good option (here an example and some link to other tables: Morte e Mutilazione).

Another very quick system could be this one: calculate the number of hp beyond zero and roll as many HD as needed to match that numbers of points, the number of needed HD represent the severity of the wound. To get back the ability to recover that HP you must first fully heal that wounds. 1HD need 1 day, 2 HD 1 week, 3 HD 1 month, 4 HD 1 season, 5 HD 1 year (heal), 6 HD permanent (regeneration), 7+ HD death.

Diseases and Poisons
A disease will block the recovery of 1 or more HD, each disease will have it's special effects.

E.G.: The red death: who gets this disease will have to do one saving vs death (or a Constitution save) each day for 15 days in a row, for each failed save he will lose one HD (zero HD means death). If the character don't die after 15 days he will recover one HD each day of full rest.

Energy Drain
Energy Drain will take away HDs (instead of levels) at 0 HD the character will die and possibly come back as an undead, such HD will be recovered only by the use of "restoration" or "wish" spells.

Designer's Notes
The idea of this rule come from the necessity to synchronize the rules for magic (presentend in the article Recharging Spells a Vancian optional system for AD&D and OSR)  with the rules for HP.

The overall guiding idea is to change the economy of innate character resources by giving more resources to low level characters and lesser resources to high level character and at the same time without changing the economy of the resources that the characters can use in a single encounter.

The net effect hoped for is to have a more homogeneous feel when playing low level characters (1-6) and high level characters (14+).

Enjoy!