In Old School RuneScape Leagues VI, defeating Doom efficiently with a mage build revolves around sustain, positioning, and understanding phase mechanics. This guide with OSRS gold breaks down a consistent, repeatable method that prioritizes survivability while maintaining strong damage output—especially during the critical later waves.

Core Build and Relics
Your setup should focus on water-based spellcasting and self-sustain. Two key mechanics define this strategy:
· Rune-based healing: A relic or effect that restores health per rune spent ensures constant passive healing.
· Damage-based healing: The upgraded demonic axe variant that heals for a percentage of damage dealt (around 60%) is essential for tanking mechanics later in the fight.
These two effects combined allow you to sustain through otherwise punishing damage windows. Additionally, prioritize:
· Prayer penetration: This significantly increases kill speed by allowing your magic damage to bypass Doom’s protection prayers.
· Spellbook speed or casting acceleration: Faster casts directly translate into more healing and higher DPS.

Recommended Gear and Switches
While mage is your primary combat style, bringing a ranged switch is highly recommended. Options include:
· Sunlight Hunter’s Crossbow
· Magic Shortbow
· Any fast, reliable ranged weapon
This is crucial for handling specific mechanics like Molten Earth, where mage-based interactions are inefficient or bugged.
A Shadowflame Ward is also strongly recommended for defensive utility, though it should not be used during certain mechanics (explained below).

Positioning and Early Waves (1–4)
For the first few waves, keep your positioning tight:
· Stay within 2–3 tiles of Doom
· Maintain consistent damage with water spells
· Focus on correct prayer switching and basic movement (dodging falling rocks)
At this stage, the fight is straightforward. Your healing effects should comfortably offset incoming damage, even with mid-tier gear.

Wave 5 Transition: Controlled Positioning
Wave 5 introduces a key shift in strategy. Instead of free movement, begin guiding Doom toward a wall. The goal is to:
· Trap Doom in a predictable position
· Minimize movement
· Maximize uninterrupted DPS
Once pinned, you can “camp” damage with minimal repositioning, significantly increasing efficiency.

Molten Earth Mechanic
During certain phases, Doom triggers Molten Earth, spawning destructible objects that must be cleared.
Important notes:
· Do NOT use Shadowflame Ward here-it only interacts for a single tick and provides negligible benefit.
· Switch to your ranged weapon to quickly destroy the objects.
· Failing to handle this properly can result in heavy damage or wasted time.

Wave 6+ Optimization: Tile Manipulation
Advanced efficiency comes from precise tile usage, commonly referred to as the “6–7 tile method.”
Execution:
· Stand on a marked tile (6–7 reference point).
· Bait Doom into initiating an attack sequence.
· The first major slam (Molten Earth smash) will deal zero damage due to positioning.
· Use this window to unload maximum DPS while overhealed.
This interaction is critical-it effectively converts a dangerous mechanic into a free damage phase.

Sustaining Through Damage
Beyond wave 8, incoming damage spikes significantly, especially from:
· Double rock mechanics
· Poison saturation across the arena
Your survival depends on:
· Maintaining overheal (often exceeding base HP significantly)
· Correct prayer usage
· Trusting your healing loop (rune + damage-based sustain)
If the arena becomes too saturated with poison, simply reposition to a cleaner section and continue the fight.

Movement Mechanics: Double Rock Dodge
A key survival technique involves alternating between:
· A safe tile (no shadow)
· A marked danger tile (with shadow)
This movement pattern allows you to reliably avoid double boulder attacks, one of the most common sources of failure.

Farming Strategy and Rewards
If your goal is efficiency rather than pushing depth:
· Farm waves 1–8 repeatedly
· Avoid deep delves unless completing tasks
Deep delves currently provide inconsistent rewards and are not optimal for farming high-value drops like completion gauntlets. Many players report significantly better results from short, repeatable runs.

Final Notes
This mage strategy works because it converts Doom into a controlled encounter rather than a reactive one. By combining sustain mechanics, prayer penetration, and positional manipulation, you minimize risk while maximizing uptime. If you’re struggling early on, repetition is key—especially for learning rock timings and movement patterns with OSRS items for sale. Once those fundamentals click, this method becomes one of the most consistent ways to farm Doom efficiently in Leagues VI.