Gruul Raid Guide (Blackrock Foundry)

Overview

• Gruul alternates two phases on a fixed timer: roughly 70 seconds of tanking, then roughly 30 seconds where he rampages in the middle of the room.
• What wipes raids: Inferno Slice landing on too few players, tanks clipping the raid with Overwhelming Blows, and petrified players standing together.
• Tanks swap and carry Inferno Slice into a soak group, healers cover the rampage, everyone spreads on Petrifying Slam.

Gruul

Abilities

• Inferno Slice: cast whenever his rage bar fills, around every 16 to 17 seconds. It hits the tank hard and splits heavy Fire damage among everyone else in a cone in front of him, leaving a debuff that makes the next Slice hurt more, plus a burn.
• Overwhelming Blows: heavy Physical hits on the tank that also strike anyone within 10 yards, with a stacking vulnerability. Forces tank swaps.
• Petrifying Slam: knocks players around and starts turning several of them to stone over a few seconds, slowing them as it progresses. Once they are stone, Shatter makes each one damage allies within 8 yards.
• Overhead Smash: a marked line in front of him that deals heavy Nature damage shortly after. Step out of it.
• Cave In (no confirmed spell link in our data): opens the second phase, dropping rocks across the room in a marked order. Each spot is hit only once.
• Destructive Rampage: for the rest of phase two Gruul stands in the center, pulses light raid damage and keeps throwing Overhead Smash in random directions. He cannot be tanked during this.

Phases

Phase one is the tanking phase with Inferno Slice, Overwhelming Blows, Petrifying Slam and the occasional Overhead Smash. Phase two starts with Cave In, then Destructive Rampage. The cycle repeats regardless of boss health, and the encounter has a 6 minute hard enrage with no soft enrage. Icy Veins suggests Bloodlust on the pull, since there is no better window.

Tank

Hold Gruul at least 10 yards from everyone, including the other tank, facing away from the raid. Wait until the last moment before Inferno Slice, step into one of the two soak groups, then step straight back out so Overwhelming Blows does not hit them. Alternate groups each Slice and swap tanks regularly on Overwhelming Blows. The off tank stays clear of both the Slice cone and the Blows radius.

Healer

Split into two even soak groups on opposite sides of Gruul so no single Slice can hit both. Expect the Slice burn on one group at a time, and keep cooldowns for the rampage phase, where damage is steady and everyone is moving.

DPS

Stay in your soak group in melee range. On Petrifying Slam, petrified players spread at least 8 yards apart and everyone else moves 8 yards from them; you have only a few seconds before the slow makes moving hard. In phase two, move into the first area that rocks have already hit, then dodge Overhead Smash lines. Avoid standing at the very edge of the room when Cave In starts, since the first safe area may open on the far side.

Difficulty notes

Mythic adds Flare: furnaces around the room launch fireballs along fixed lanes, hitting anyone in the path and leaving a stacking Fire vulnerability. The furnaces themselves also burn anyone standing in front of them when they fire. Mythic also fills Gruul's rage faster (a Slice roughly every 12 to 14 seconds), gives him 50 rage instantly if an Inferno Slice hits fewer than 4 players, and makes Petrifying Slam affect the whole raid, so everyone spreads 8 yards apart after the knockback. Because the Slice debuff still lasts 30 seconds, each soak group takes two Slices in a row instead of alternating, and solo soaks with immunities no longer work. Icy Veins describes two layouts that keep everyone out of the Flare lanes: the whole raid in one half of the room with little space, or Gruul at the crossing of the three lanes with the tank on one side and the raid on the other, which gives more room but forces the tank through the lanes for each Slice. Anyone hit by a Flare should skip Slice soaks until the Fire vulnerability falls off.

Soloing today: we found no reliable current source on solo specifics for this boss, so we are not making claims about it beyond the normal mechanics above.

Loot highlights

Items from this encounter's loot table in our journal data:

• Meaty Dragonspine Trophy: Agility trinket (Heroic and Mythic).
• Taner's Terrible Spine: Strength one-hand sword.
• Inferno-Flame Staff: caster staff.
• Gruul's Lip Ring: caster necklace.
• Gronn-Skin Crown: mail helm.
• Gronn-Stitched Greatcloak: tank cloak.

Common mistakes

• The tank lingering in a soak group after Inferno Slice and stacking Overwhelming Blows on DPS.
• Both soak groups standing where one Slice can reach them.
• Petrified players running into each other or into the raid.
• Running into fresh rock markers in phase two instead of an area that already fell.

Mechanics checked against: icy-veins.com, warcraft.wiki.gg. Ability names and spell IDs come from TheWoWDB's own client datamine.