Great Olm

The Great Olm (referred to as the Guardian in the Deep by Xeric's followers) is the final boss in the Chambers of Xeric raid. A large, blind, white salamander, it is one of Xeric's greatest possessions.

Mechanics

Attacks

• Standard attacks: Olm has two standard attacks: Magic and Ranged. The magic attacks are large green orbs, while the ranged attacks are smaller chunks of crystal. Both deal the same amount of damage. Prayer reduces the damage by roughly 75-80%.
• Spheres: Olm randomly picks a sphere (red, green or purple) and sends it at the player. If not blocked, the player will be damaged approximately 50% of their current Hitpoints. If a protection prayer was used when the sphere was launched, it is disabled and the player's Prayer is reduced by 50%. To block the attack, pray accordingly before and as the sphere hits you:
  • Red (sphere of aggression): Protect from Melee
  • Green (sphere of accuracy and dexterity): Protect from Missiles
  • Purple (sphere of magical power): Protect from Magic

During phases 1-3, Olm also has access to these specific attacks:

• Crystal Burst: Olm throws a crystal seedling under every player in the chamber. A few seconds later, the crystals burst and shove the player to a nearby tile if they are on top of them for heavy damage. The left hand will briefly show a crystal icon when using this attack.
• Lightning: Shoots out lightning running north and/or south of the chamber. Getting hit by a bolt of lightning electrocutes the player, disabling their overhead prayers, dealing moderate damage, and binding them. The left hand will briefly show a lightning bolt when using this attack.
• Swap: Olm will perform a teleport attack that deals damage the further the player is from the target. The left hand briefly shows a swirl when using this attack. If alone, Olm will pick a random tile anywhere in the chamber; if there are more players in the room, Olm will evenly distribute the amount of teleports. If there is an odd-numbered amount of people inside, then those people will not be subjected to the attack.

Olm also has phase-unique attacks which can replace one of the auto-attacks in his rotation:

• Acid:
  • Acid Spray: Olm spits out several pools of acid around the chamber. Standing on top of an acid pool deals 3-6 damage per tick and inflicts poison starting at 2 damage.
  • Acid Drip: Olm covers a player in acid, causing them to generate acid pools under them. Standing still will deal damage and moving will generate more pools, though it is not much of a deal in small groups. The pools function the same way as the pools in the spray attack.

A group of players fighting the Great Olm.

• Flame:
  • Deep Burn: Olm shoots out a green fireball at a player, causing them to yell "Burn with me!". The targeted player takes 5 damage every few ticks, dropping stats by 2 each time this occurs for six hits. If it spreads to other players, the timer resets and newly infected players will initially yell "I will burn with you."
  • Fire Wall: Olm shoots out two walls of fire at a player to trap them. If the player is on a tile that would be occupied by the fire wall, they will leap out and take 8-10 damage in the process. After the walls are placed, players in the tiles between the two walls will take 50-65 damage in 5 seconds if they do not escape. Any water, such as water spells, ice spells, Humidify or a filled watering can will suffice in dousing a segment of flame.
• Crystal:
  • Falling Crystals: Olm lets out a cry, targeting one player with a red aura. 11 spiked crystals fall from above, dealing up to 15-20 damage to anyone in the targeted tile.
  • Crystal Bombs: Olm shoots out a crystal bomb (up to three at most; two for smaller groups). The bomb explodes after being deployed for several seconds, covering a radius of four tiles. The minimum amount of damage dealt is 15, increasing by an additional 15 damage for every tile closer to it.

There are also attacks applied during other segments of the fight:

• Autoheal: During the first three phases, any attacks aimed at the head are completely healed after several ticks have passed. In the third phase, the left arm also gets a variant of this ability where any attacks that deal damage will cause it to heal instead. When this is performed the left hand shows an infinity symbol.
• Falling Crystals: During phase transitions and the last phase, Olm causes chunks of crystal to fall from above. These crystals have a 3x3 AoE; getting directly hit (underneath the shadow) by them will deal 16-25 damage, while getting indirectly hit (one tile from centre) deals 10-16 damage. One crystal will always be aimed at a random player in the chamber. A shadow will indicate where the crystal will land.
• Life Siphon: In the last phase, Olm will shoot out two blue projectiles which generate a shield when it hits the ground. Several ticks later, Olm will damage anyone not on the targeted tiles for moderate damage, healing himself for five times the total amount of damage it deals to the team.

Fight overview

The mystical barrier which precedes the boss fight.

Olm has at least four phases, with an additional phase for every 8 players in the raid. Unlike the other bosses in the room, once the player enters his chamber, it is a fight to the death. In each phase except the penultimate and final ones, Olm will focus on a specific set of abilities referred to as powers.

Like other bosses in the chambers, many of Olm's stats scale between its claws and head depending on the stats and amount of players in the raid, despite him having a pre-determined combat level. Monster Examine can be cast on him. In most small teams, his combat stats and max hit are comparable to God Wars Dungeon bosses. If stat draining attacks — such as dragon warhammer special attack — are used, they only affect the part of him that was hit. His stats also reset when a new phase starts.

Olm attacks with ranged and magic, the former consisting of a chunk of crystal and latter green-coloured dragonfire. There is a 1/5 chance the Great Olm will switch between these attack styles each time its head performs an attack. Olm has three attack zones to choose from; left, middle and right. He prioritises the zone with the most amount of players. If no players are in that zone, he will swerve his head accordingly and skip an attack in its attack rotation. If a player is in his attack zone but Olm swerves his head regardless, no attacks are skipped.

Olm's attack rotation consists of the following below. Phase-specific attacks are incorporated into the attack pattern as an auto-attack and alternate between the available pool:

• 2 auto-attacks
• Crystal Burst
• 2 auto-attacks
• Lightning
• 2 auto-attacks
• Teleport
• Loops from above

There is a 1/3 the Great Olm will carry out a phase-specific attack in lieu of an auto-attack (provided they are not on cooldown), increasing to a 1/2 chance during the final phase of the encounter. When this roll succeeds, the Great Olm will consequently try to avoid picking any of the available phase-specific attacks it has already used before.

In order to progress to the next phase, both of Olm's hands must be disabled. The Olm's left hand will clench if it takes a particularly heavy hit, equal to at least 1/20 of its base health. Olm's head can be attacked at any phase, although he will automatically recover any damage taken shortly afterwards in all but the final phase. When both hands are disabled, Olm will retreat underground and shake the area with AoE falling crystals before reappearing on the other side with a new power. During the penultimate phase, the left hand gains a damage to health ability indicated with an infinity sign on it. In this phase, both of Olm's hands must be disabled within a specific time frame or it will recover back at full health. All powers are available to Olm during this phase, and it is indicated with Olm's head glowing.

Once both hands are disabled, Olm remains on the spot and attempts a final stand. AoE crystals will continually fall from above until Olm is killed. As with the previous phase, he has access to all of its powers.

Equipment

Note: The equipment layouts below is for melee only, with magic and ranged switches in the player's inventory due to all three combat styles being required.

Recommended equipment for Melee

Slot	Item (most effective → least effective)
	Torva full helm	Neitiznot faceguard	Inquisitor's great helm	Serpentine helm
	Amulet of torture	Amulet of blood fury	Amulet of fury	N/A
	Infernal cape	Fire cape	N/A	N/A
	Torva platebody	Bandos chestplate	Inquisitor's hauberk	Fighter torso
	Torva platelegs	Inquisitor's plateskirt	Bandos tassets	Blessed chaps
	Scythe of vitur	Dragon hunter lance	Abyssal tentacle/ Ghrazi rapier	Osmumten's fang
	Avernic defender	Dragon defender	N/A	N/A
	See Ranged	N/A	N/A	N/A
	Ferocious gloves	Barrows gloves	N/A	N/A
	Primordial boots	Dragon boots	N/A	N/A
	Lightbearer	Ultor ring	Berserker ring (i)	Brimstone ring
	Bandos godsword	Dragon warhammer	Arclight	N/A

Recommended equipment for Ranged

Slot	Item (most effective → least effective)
	Masori mask (f)	Armadyl helmet	Void ranger helm	Any melee helmet
	Necklace of anguish	Amulet of fury	N/A	N/A
	Dizana's quiver Dizana's quiver	Ava's assembler	Ava's accumulator	N/A
	Masori body (f)	Armadyl chestplate	Blessed body	Elite void top
	Masori chaps (f)	Armadyl chainskirt	Blessed chaps	Elite void robe
	Twisted bow	Dragon hunter crossbow	Zaryte crossbow	Armadyl crossbow
	Twisted buckler	Dragonfire ward	Odium ward	N/A
	Dragon arrows	Ruby dragon bolts (e)	Ruby bolts (e)	N/A
	Zaryte vambraces	Barrows gloves	Void knight gloves	N/A
	Pegasian boots	N/A	N/A	N/A
	See Melee	N/A	N/A	N/A
	Toxic blowpipe	N/A	N/A	N/A

Recommended equipment for Magic

Slot	Item (most effective → least effective)
	Ancestral hat	Any melee helmet	N/A	N/A
	Occult necklace	Amulet of fury	N/A	N/A
	Imbued god cape	N/A	N/A	N/A
	Ancestral robe top	Virtus robe top	Ahrim's robetop	N/A
	Ancestral robe bottom	Virtus robe bottom	Ahrim's robeskirt	N/A
	Tumeken's shadow	Sanguinesti staff	Trident of the swamp	Harmonised nightmare staff
	Book of the dead	Tome of fire	Elidinis' ward (f)	Arcane spirit shield
	See Ranged	N/A	N/A	N/A
	Tormented bracelet	Barrows gloves	N/A	N/A
	Camp/Takeoff melee boots	N/A	N/A	N/A
	See Melee	N/A	N/A	N/A

Setups

Minimum	Medium	Max