HP

Every character has a number of health points defined by their level, their life statistic (based on choice of race), and their strength, constitution, and will attributes. Generally speaking, this value will begin low and will increase as any of those four factors increases.

Once a character's HP goes below zero, the character is slain.

The formula appears to be:

Maximum HP = 5 + Life / 100 * ( characterLevel * ( 2 * Constitution + Strength + Will / 3 ) / 25 + Constitution ) with an upper limit of 1000000

Remember that all math in this game is integer math, which means the decimal portion of calculations is always truncated. (If you should have 103.999 HP according to the formula, you will get 103 HP.) This means that, at low levels, the character level divided by seventy-five part of that formula will probably make your Strength and especially Will scores irrelevant to HP.

Temporary bonuses to life or any other HP-altering attributes from equipment, blessed potions of restore body/mind, feats, mutations, or other revocable sources all change maximum hit points. Unequipping items that give an HP-boosting attribute bonus can leave a character "overhealed" until the next time their Healing skill takes effect. Spells like the Hero spell, which grants temporary strength, however, does not add HP. Abilities that drain your attributes until restored at a healer, however, will reduce your maximum HP.

Generally speaking, Life is the most important attribute determining HP, followed by character level. Of the major attributes, Constitution is the most important, especially when your levels are low.

The Metal race (Gold Bells, Silver Bells) has the lowest health point total in the game, due to having a life rating of 1. Even these characters, however, always have a minimum of 15 hit points.

Elona+

The following formula for maximum HP is correct as of 1.75:

$\text{Maximum HP} =$

$\left( \frac{\text{Constitution} \times 3 + \text{Strength} + \text{Will}}{3} \times \frac{\text{Level}}{9} + \text{Constitution} \right) \times \frac{\text{Life}}{100} + 5$

• Contribution from level is capped at 10,000.
• Contribution from Life is capped at 1,000.
• Contribution from the following is capped at 2,000,000:

$\frac{\text{Constitution} \times 3 + \text{Strength} + \text{Will}}{3} \times \frac{\text{Level}}{9} + \text{Constitution}$

Rounding down to the nearest integer occurs after every division.

Formulae for previous versions

In version E+ 1.56:

Maximum HP = ((Constitution * 2 + Strength + Will) * Level / 20 + Constitution) * Life / 100 + 5
Level is capped at 10,000
Life is capped at 1,000
((Constitution * 2 + Strength + Will) / 4 * Level / 5 + Constitution) is capped at 2,000,000  

From Elona+ 1.47 to 1.55:

Maximum HP = 5 + Life*(Constitution + CharacterLevel (Constitution * 2 + Strength + Will) / 20) / 100