Your damage threshold is simply your Constitution score+highest class level+3 for any warrior class (fighters, dwarves, elves and halflings)+the AC bonus* of your armor. Magical AC bonuses including bracers of armor also apply, but not shields, Dexterity bonus or incremental armor class from class levels.
Léonard Tolbert is a young, if moderately experienced, warrior (4th level fighter) marching off against a small pack of demons mistakenly by a sorcerer friend of his. He arms and armors himself well before battle knowing that at least some of these hellspawn could rip him to shreds. He already has a Constitution of 14, a Strength of 17 and a Dexterity of 16 (meaning that his player probably rolled pretty well) and is wearing a suit of plate armor (AC 3). Subtracting the AC his armor gives him from nine gives Léonard a total damage threshold of 27 (14 Constitution+3 fighter+4 level+6 armor), while his armor and Dexterity give him an AC of 1.
*I know that AC in pre-3rd edition D&D is descending and most armors are given a set AC value. Just subtract a particular armor's AC from 9 and add the difference to damage threshold.
The Wounds Part of it All
The wound track measures how much severe trauma and injury a character can withstand before losing consciousness. Every attack that inflicts your damage threshold or more in hit points causes at least a single wound. A character can withstand a number of wounds equal to his or her current Constitution score and depending upon his or her current hit points before unconsciousness.
|Hit Points and wounds|
|Wounds||More Than Half Hit Points||Half Hit Points||0 Hit Points|
|0 wounds||Completely and utterly fine, unless your PC has been poisoned, petrified, paralyzed, stunned, cursed or set on fire.||Fatigued until wounds are healed.||Fatigued and sickened.|
|Wounds<1/2 Con||Fatigued until wounds are healed.||Fatigued and sickened.||Sickened and exhausted|
|Wound>1/2 Con||Fatigued and sickened.||Sickened and exhausted||Exhausted and nauseated|
|Wounds=Con score||Sickened and exhausted.||Exhausted and nauseated||Disabled or unconscious|
Healing wound damage is trickier and more difficult than healing normal hit point damage. In fact all hit point damage needs to be healed first before the character can recover from any wounds at all. After all hit point damage is recovered from characters heal their wounds at a rate of one wound for a short rest and three wounds per long rest. Effective medical care can double or even triple the rate of wound healing and magical healing can further improve treatment. For every ten hit points (rounded up) a spell would normally heal remove one wound instead.
Here it is, my attempt at a wounds system for BECM/Saga/Mutant Future Franken-game. So then, how does it look.