Vitality points (Vitality, or VP) are a measure of a character’s ability to keep dodging attacks. Vitality points go up with level, giving high-level characters more stamina to dodge and shrug off attacks. Damage reduces Vitality points first. When you run out of Vitality, you cannot avoid attacks, and so start taking Wound damage.
Characters gain Vitality points as they gain levels. At each level a character rolls a Vitality die and adds his Constitution modifier, adding the total to his Vitality point total. (A character always gains at least 1 Vitality point per level, regardless of his roll or Constitution modifier.) A player can elect to take the high average of his Vitality die (that is, half the faces of the die, plus 1), or to roll - but this choice must be made before rolling.
Vitality dice: You'll find the type of die for your character class in the class descriptions.
Wound points (Wounds, or WP) measure how much true physical damage a character can withstand. Damage reduces Wound points only after all Vitality points are gone, or when a character is struck by a critical hit. A character has a number of Wound points equal to her current Constitution score. Some types of monsters have additional Wound points based on their Wound Dice.
Base Wound Points and Hit Dice
All creatures have a base number of Wound points equal to their Constitution score, multiplied by a size factor, as per Table: Base WP by Size.
Most player characters are either Medium or Small, and so their Wound Points are equal to their Constitution scores - but halflings, although quick, are fragile, and have only 3/4 of their Constitution score for Wounds: see Races for more details.
(For monsters and NPCs, this base counts as 1 HD for the purposes of calculating saving throws, Base Attack Bonus and other statistics determined by Hit Dice - however, creatures and characters with class levels gain no benefit for this HD: those benefits are replaced by the benefits of the 1st level of their class.)
Table: Base WP by Size
|Size||Base WP multiplier|
|Large tough*||1 1/2|
*Fragile and tough creatures: A small creature with combined racial penalties to its Constitution and Strength score of more than -4 is considered fragile. A large creature with a combined racial bonus to its Constitution and Strength scores of greater than +8 is considered tough.
Also referred to as HD. There are two types of Hit Dice; Vitality Dice and Wound Dice. These represent a creature's general level of power and skill. As a creature gains levels, it gains additional Hit Dice. Monsters, on the other hand, gain racial Hit Dice, which represent the monster's general prowess and ability.
Player characters and some quick or magical monsters gain Vitality Dice at each level. Some physically tough monsters have only Wound Dice. Lastly, there are some creatures that, like Player Characters, have both Vitality and Wound Dice. The number of Hit Dice for a creature is equal to the total number of Vitality and Wound Dice that a creature has.
Both types of Hit Dice are represented by the number the creature possesses followed by a type of die, such as “3d8.” This value is used to determine a creature's total Vitality or Wound points depending on the type.
The term Hit Dice is used synonymously with Level. Like class levels, the more Hit Dice a creature has, the more powerful it is.