The Hunters of Ara
Vitality is special type of resistance that represents the ability to resist continuous negative effects, such as ongoing damage and de-buffs that require a Saving Throw to negate.
The amount of Vitality a character has is determined by Heal/5 + Endurance/10, i.e. one Vitality point per every 5 points in Heal and 1 Vitality point per 10 points in Endurance.
Each point in vitality reduces the damage done (per tick) of ongoing damage effects on you. It can therefore be thought of as resistance (such as Physical Resistance and Magical Resistance) for ongoing effects (as the other resistances do not reduce ongoing damage). Like the typical resistances, this effect ‘stacks’ on multiple sources of ongoing damage: for each source on ongoing damage, each time you would take damage from this source the damage is reduced by the amount of points in Vitality. That means that if two sources on ongoing damage are on a character at the same time, the Vitality resistance has double effects, and so on for multiple sources.
Finally, each 5 points in Vitality also gives +1 bonus to all Saving Throws.