Adrenaline

Certain Warrior and Paragon skills are fueled by adrenaline rather than energy. It is gradually built up each time the Warrior or Paragon hits or is struck in combat, each such blow being added to the characters adrenaline level. Some skills increase the rate of adrenaline build up, while others expend it entirely.

Adrenaline Points
Adrenaline is not actually gained in strikes, but in points. Every adrenaline skill stores its own adrenaline points displayed by rising flames from 0 until fully charged. See this table for number of adrenaline points needed for skills.

1 4 "strikes" on Cleave does not equal 4 "strikes" on Sever Artery. The "Points needed" column increases linearly; the "adrenaline strikes needed" in the skill descriptions are a simplification. A "strike" of adrenaline in the skill description equals 20-25 points. A real "strike" of adrenaline gives 25 points.

All paragon skills cost (25*strikes needed) 'points'.

Gaining adrenaline
Gaining adrenaline means every adrenal skill in your bar gains that many points.
 * For every attack you make that hits, you gain 25 adrenaline points.
 * For every 1% of health lost from your maximum, you gain 1 point of adrenaline. Runes count against the maximum health. Gain is calculated on a per-attack basis.
 * For every 25% of your health lost, you gain approximately 1 "strike" of adrenaline--the equivalent of an attack landing. Note that health lost includes ranged attacks but excludes health degeneration. Commonly, 4 strike skills are charged in about 3 hits time, because you take some damage at the same time, assuming that the opponent is attacking you.

Using adrenaline
You can only use adrenal skills that are fully charged with adrenaline. They cost 0 Energy. When you use an adrenal skill, that skill's adrenaline pool is emptied, and all other adrenal skills in your bar lose 25 points. These lost 25 points can be recovered with your next hit (including the adrenaline-fueled attack itself), or by taking as much damage as 25% of your maximum health.

Losing adrenaline
Losing adrenaline means every adrenal skill in your bar loses its full load of adrenaline. For attack skills with this attribute, the effect comes after the 25 points each skill gains if the attack hits, so all pools will be at 0. You lose all adrenaline after you have not been attacked, do not attack, or otherwise gain adrenaline (eg. Rage of the Ntouka) for 20 seconds, or when you die.


 * Some warrior skills cause "...lose all adrenaline." These skills are: Hammer Bash, Heavy Blow, Wild Blow, Final Thrust, "On Your Knees!", Battle Rage, Shove,  Burst of Aggression and Decapitate.
 * Any adrenal skill which is reset, disabled or recharging will lose all adrenaline and will not gain any new adrenaline until it has recharged. Diversion, and Shield Bash can be used to disable individual skills. Blackout and Wail of Doom can disable multiple skills of an opponent. Bestial Fury, Primal Rage, Shove, Marauder's Shot, and Tiger's Fury can disable your own skills. Quivering Blade and Whirling Axe are disabled if blocked.
 * Sympathetic Visage and Ancestor's Visage causes a loss of all adrenaline for all adjacent foes when the enchanted ally is struck by a melee attack.

Related articles

 * Gain adrenaline skills quick reference
 * Adrenaline skills quick reference
 * Adrenaline denial

Reference
Research done by Ensign and Silmor. Original GW Guru thread. Further discussion and research.