Andrew Bartlett 20th April 2015 v1.0

House Rule #1

Ascending Hit Points: an alternative Hit Points rule for Classic ‘Old School’ RPGs

This being a document that describes an alternative HP system designed with the intention of making mortal combat more uncertain and risky, while retaining the core concepts of Classic ‘Old School’ RPGs, namely Hit Dice (HD) and Hit Points (HP).  

PCs, NPCs, and Monsters – Characters – have Hit Dice (HD) as is traditional. However, these are not rolled to generate Hit Points (HP) as is ordinarily the case.

Rather, HP for each Character start at 0. Events that would traditionally cause HP ‘damage’ add to a running HP total for that Character. After adding these HP the Character’s HD are rolled. If the HD roll is equal to or greater than the current HP total, the Character can fight on. If the total rolled is less than the Character’s HP total, consequences ensue. This is the equivalent of reaching 0 HP using the traditional system. In a brutal campaign the Character has been killed. More generous Referees ought to allow PCs (and select NPCs and Monsters) to roll on a Death & Dismemberment table when a HD roll is failed.

Rollo the 3rd level Fighter has 3HD, and a Constitution of 14, giving him a +1 HP modifier per HD. Fresh and rested with 0 HP, Rollo leaps into a fight with an Orc. The Orc ‘hits’ Rollo with his sword, rolling 8 points of HP ‘damage’. Rollo now has a total of 8 HP. Rollo’s Player rolls his HD (3d8+3), which gives Rollo a possible score of 6-21. If he rolls 8 or more, which as a third level fighter is likely, Rollo will fight on. If he rolls 7 or less, Rollo has either been taken out of the fight, or faces a roll on a Death & Dismemberment table. If Rollo is hit again for 1HP ‘damage’, he would have a total of 9HP and would his HD would be rolled once more.


Combat in D&D can feel like a back and forth of HP attrition, with some Characters having HP ‘padding’ such that the Players and Referee can be certain that the next blow (or the next several blows) will not, under any circumstances, ‘take out’ those Characters. Under this system, these Characters are at greater risk when they are ‘hit’, but the main nuts and bolts of the system have not undergone too radical a change. Higher HD still protects Characters, HP ‘damage’ can still be understood in the same way (and so healing can operate in the same fashion), and there is no extra bookkeeping, with the ‘Hit Points’ box on the character sheet only changing in that the number it tracks now increases rather than decreases. There is an extra dice roll each time a Character is ‘hit’, but the dice to be rolled only change when the Character increases (or decreases!) in Level, and adding up a running HP total is (marginally) easier than subtracting from a HP score. If the Death & Dismemberment table is suitably ‘generous’ – with a high probability of [temporarily] disabling conditions – not only is it possible for the PCs to lose fights in ways that fall short of death, but HP recovery be made much easier (using the ‘short rests’ and ‘long rests’ of later editions of the Classic RPG, for example), which permits a different rhythm to adventure and exploration while maintaining a suitably gritty tone.

Consequences and Corollaries

What should be borne in mind is that multiple ‘hits’ are now substantially more dangerous – each ‘hit’ not only increases the HP total but requires a fresh HD roll against the new total, each with a new ‘opportunity’ for failure. Taking a total of x points of HP ‘damage’ from four different wounds is substantially more dangerous than taking x points of HP ‘damage’ from a single wound. This is a feature of this system, not a bug, but GMs should take care not to inflict HP ‘damage’ for trivial events. Or, at least, the Referee ought not require a HD roll in these circumstances as it is never just 1HP damage when using this system.

Despite appearances, this system is not intended to kill PCs. As has been recommended, rolling on a ‘generous’ Death & Dismemberment on a failed HD roll is one way to maintain risk while reducing outright lethality. Referees might also considering allowing Classed Characters to use the higher HD of the ‘Advanced’ versions of Classic ‘Old School’ RPGs (in which a Fighter rolls d10, Clerics d8, Thieves d6, and Magic Users d4). This keeps the element of risk – the low end of the HD roll remains the same while shifting the mean and the maximum of a Character’s HD roll slightly higher. Alternatively, Classed Characters can be given a Level 0 HD, typically d6, in addition to their Class HD.