In Lineage II, as long as you have Vitality you can get XP and SP from killing monsters. Vitality does not affect XP earned from quests. If you have no Vitality points at all you suffer from a XP and SP penalty.
Vitality is unique to each character and their class mode. For example, your character has one Vitality points pool on their main class, but they have a separate one for their Dual Class and each of their Subclasses. This same character/class-specific system applies to Vitality items. Vitality also stacks with other XP-related items such as XP/SP Runes and other boost consumables.
Vitality is restored once per week at 6:30 a.m. (server time) every Wednesday (coinciding with, but separate from, the regular weekly server maintenance). Vitality is consumed over time as the character earns XP from killing monsters.
Vitality can also be restored by using Vitality Items.
Vitality items can be found in-game as herbs during server events, from treasure chests, or dropped from monsters. You can also purchase Vitality items to use when you wish from the L2 Store in-game.
These replenish a fixed amount of Vitality. The amount replenished depends on the item used.
These items recover Vitality as XP is earned by killing monsters. The amount recovered is the same amount that would be consumed without the Vitality Recovering effect.
This item maintains Vitality at its current level for as long as the maintaining effect is active.
This item suspends Vitality for as long as the suspending effect is active. While Vitality is suspended, players do not earn any bonus from Vitality, and Vitality is not consumed when hunting monsters. This item is especially useful if you decide to save your Vitality points for later instead of using them now.
To use a Vitality item, right-click on the item in your character’s inventory. Depending on the item used you will see a system message telling how many more Vitality items can be used this week.
Most Vitality items also have a cooldown timer which is usually 60 minutes or 30 minutes long, but this can vary depending on the item.