Combat Mechanics referring to combat resources are listed here. A combat resource is defined as a resource the player needs to successfully perform actions.
Health Points (HP)
The singular most important resource a player has. When the player's HP reaches zero, they are killed and respawn at the last bonfire they rested at, or returned to their world. In PvP encounters, the win condition for the player is for their opponent's HP to reach zero before theirs. In PvE, a Boss is only defeated once their HP reaches zero.
HP can be gained through levelling the Vigor attribute, equipping the Ring of Favor and equipping the Life Ring.
HP is restored by sitting at bonfires, using healing Estus, Siegbrau, Divine Blessings, casting healing spells, casting regeneration spells or having regeneration items equipped.
The player's maximum HP will be increased by 30% when in the "Embered" state. A player can enter the Embered state by defeating a Boss, using an Ember or defeating a Host of Embers.
Stamina
The resource a player consumes to perform an attack, cast a spell, roll, backstep, sprint or block an attack. Stamina regenerates over time.
Stamina is gained through levelling the Endurance attribute or equipping the Ring of Favor.
The rate at which stamina regenerates can be increased with Green Blossoms (and all variations), equipping the Chloranthy Ring or being under the effect of Deep Protection. It can also be decreased by being under the effects of Impact, Frostbite, equipping the Greatshield of Glory or by increasing equipment load past 70%.
If a player performs one of the listed actions without the sufficient stamina, they will enter a state of negative stamina, where they cannot perform another action that consumes stamina until they have regenerated their "stamina debt" back.
Focus Points (FP)
The resource a player consumes to cast spells or use most Weapon Arts. If the player lacks the required FP, the action will not occur.
FP can be restored by siting at bonfires, drinking Ashen Estus, using Hidden Blessings or by having Arcane items equipped.
Poise
A modifier applied to hyper armour that can be gained from equipping armour, the Lothric Knight Long Spear, Wolf Ring, Dragon Tooth, or Yhorm's Greatshield. Also gained by being in Dragon Form.