PoE2
Fist of War
Support
Attack, Melee, Slam
Cost Multiplier: 140%
Requires: Level 1
Support Reqirements: +5 Str
Supports slam you use yourself, providing a powerful Ancestral Boost every few seconds.
Attacks with Supported Skill are Ancestrally Boosted, no more than once every 6 seconds
Place into a Skill's Support Gem socket in the Skills menu to apply its effects to that Skill. You cannot have multiple copies of the same Support Gem socketed at the same time.
PoE1
Fist of War Support
Slam
Attack, Melee, AoE, Support
Level: (1–20)
Cost & Reservation Multiplier: 140%
Requires: Level (38–70), (63–111) Str
Supports slam skills, providing a powerful boost when they're used, with a delay before they can be boosted again. Cannot support Vaal skills or triggered skills. Cannot modify the skills of minions. Only skills you use yourself can receive the boost.
Attacks with Supported Skill are Ancestrally Boosted, no more than once every (1.8–2.5) seconds
Ancestral Boost does not apply to repeats of the Attack
Ancestrally Boosted Slams have (40–59)% increased Area of Effect
Ancestrally Boosted Slams deal (70–98)% more Damage with Hits and Ailments

Additional Effects From Quality:
Supported Skills have (0–10)% increased Area of Effect
This 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 Skill Gem you wish to augment. Right click to remove from a socket.