Considering helping out on the wiki to keep it updated - in particular the changed unique items need to be updated to reflect 2.6.0 changes.
Mods and base items have been updated to 2.6 values - skill progressions on some skill gem pages may need updating or some bugs need to be fixed.
FrenzyAttack, Melee, Bow
Mana Cost: 10
Cast Time: 1.00 secRequires Level 16Acquisition
Level: 16Performs an attack that gives the character a frenzy charge if it hits. Frenzy charges increase your attack speed.Per 1% Quality:
0.5% increased Attack SpeedDeals (110-136.6)% of Base Attack Damage
5% increased Physical Damage per Frenzy Charge
5% increased Attack Speed per Frenzy ChargePlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.
The bread and butter of any effective combat skill set, Frenzy is used by many and feared by all. With Frenzy active, every successful attack dealt accelerates the next attack, transforming the player into an offensive dervish. Once the Frenzy is at full intensity, it can be maintained indefinitely as long as the player strikes a new target in time. Several skills consume Frenzy charges when they are activated, enabling new ways to decimate foes.Description on the official Path of Exile website 
Frenzy is an attack that grants frenzy charges on hit and also gets large bonuses from them. Frenzy is not the only skill that grants frenzy charges, but it is a good way to build them quickly. A Frenzy attack may be performed with any weapon type or unarmed.
Skill Functions and Interactions
- Dual Wielding: Dual wielding attacks with Frenzy will alternate weapons each attack.
- Increased Physical Damage per Frenzy Charge: When you use Frenzy (the skill) to attack an enemy, you will receive a bonus to the physical damage done by that attack based on how many frenzy charges you had before using the skill.
- Increased Attack Speed per Frenzy Charge: When you use Frenzy (the skill) to attack an enemy, you will receive a bonus to the attack speed of the attack based on how many frenzy charges you had before using the skill. Note that frenzy charges grant +4% attack speed per charge to any attack, which also apply to attacks made with Frenzy (the skill). So, if you have two frenzy charges, you will get a total of 18% (2 * 5% + 2 * 4%) increased attack speed with your next attack made with Frenzy, but only a 8% increased attack speed bonus with any other attack that does not have a similar bonus.
- Multiple Projectiles: When Frenzy is used with a ranged weapon and multiple enemies are hit, only one frenzy charge maximum will be gained per use of the skill.
- Melee Splash: Only one Frenzy charge will be granted no matter how many enemies are hit by it.
- Multistrike: Only one Frenzy charge can be granted per sequence of attacks.
- Despite its Melee tag, its damage is not increased by linking it to melee support gems while using a bow. This includes Melee Damage on Full Life SupportMelee Damage on Full Life SupportMelee, Support, Attack
Mana Multiplier: 130%Requires Level 18Acquisition
Level: 18Per 1% Quality:
0.5% increased Melee Physical DamageSupported Melee Skills deal (30-49)% more Melee Physical Damage when on Full LifeThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Active Skill Gem you wish to augment. Right click to remove from a socket., Melee Physical Damage SupportMelee Physical Damage SupportMelee, Support, Attack
Mana Multiplier: 140%Requires Level 18Acquisition
Level: 18Per 1% Quality:
0.5% increased Melee Physical DamageSupported Melee Skills deal (30-49)% more Melee Physical DamageThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Active Skill Gem you wish to augment. Right click to remove from a socket. and Multistrike SupportMultistrike SupportAttack, Melee, Support
Mana Multiplier: 180%Requires Level 38Acquisition
Level: 38Per 1% Quality:
0.5% increased Melee Physical DamageSupported Melee Attacks Repeat 2 additional times
(75-94)% more Melee Attack Speed
30% less Attack DamageThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Active Skill Gem you wish to augment. Right click to remove from a socket.. However, the mana cost will increase as normal. Such gems will function with a melee weapon.
Gem level progression
Quest rewardThis skill is given as quest reward for the following quests:
|Intruders in Black|
Vendor rewardThis skill can be bought at the listed npc vendors after completing the following quests:
|The Root of the Problem|
|A Fixture of Fate|
Related helmet enchantments
The following helmet enchantments affect Frenzy:
|EnchantmentFlickerStrikeDamagePerFrenzyCharge1||66||6% increased Flicker Strike Damage per Frenzy Charge|
|EnchantmentFlickerStrikeDamagePerFrenzyCharge2||75||9% increased Flicker Strike Damage per Frenzy Charge|
|EnchantmentFrenzyDamage1||66||25% increased Frenzy Damage|
|EnchantmentFrenzyDamage2||75||40% increased Frenzy Damage|
|EnchantmentFrenzyDamagePerFrenzyCharge1||66||6% increased Frenzy Damage per Frenzy Charge|
|EnchantmentFrenzyDamagePerFrenzyCharge2||75||9% increased Frenzy Damage per Frenzy Charge|
|EnchantmentFrenzyPercentChanceToGainAdditionalFrenzyCharge1||66||20% Chance on Frenzy to gain an additional Frenzy Charge|
|EnchantmentFrenzyPercentChanceToGainAdditionalFrenzyCharge2||75||30% Chance on Frenzy to gain an additional Frenzy Charge|
- "Dexterity skills". Official Path of Exile website.