OSRS Thermonuclear Smoke Devil Guide (Thermy)

The Thermonuclear Smoke Devil, often called "Thermy," is the boss variant of the Smoke Devil Slayer monster. Requiring a high Slayer level of 93 to damage, Thermy resides in its own lair within the Smoke Devil Dungeon. It's known for its unique drops, including the powerful Occult Necklace and Smoke Battlestaff.

Requirements & Location

  • Skill: 93 Slayer (non-boostable).
  • Task: Must be on a Smoke Devil Slayer task (assigned by Duradel, Konar, or Nieve/Steve). Exception: One kill off-task is allowed for the Western Provinces Diary completion, but still requires 93 Slayer.
  • Item: Facemask, Slayer Helmet, or Gas Mask is mandatory to avoid constant smoke damage inside the dungeon and boss room.
  • Location: Smoke Devil Dungeon (south-west of Castle Wars). Enter the cave, head north-west past regular smoke devils, enter the crevice to the boss lair.
  • Getting There: Ring of Dueling (Castle Wars teleport) + run SW, or Fairy Ring code BKP + run NE.

Mechanics

Thermy itself is mechanically simple, but its attack style is unique:

  • Attack Style: Typeless Magical Ranged.
    • Typeless: Protection prayers (Protect from Magic/Missiles) have no effect on damage reduction.
    • Magical Ranged: The attack's accuracy is calculated using Thermy's Ranged Attack bonus against the player's Magic Defence bonus.
  • Attack Speed: Extremely fast (2 ticks, or 1.2 seconds).
  • Max Hit: Low (8 damage).
  • Defence: Very high Magic and Ranged defence bonuses. Extremely low Melee defence bonuses. Melee is strongly recommended.
  • Movement: Can walk through players/other NPCs (prevents safespotting with minions).
  • Cannon: Cannot be used in the boss room (will be destroyed if placed).

Strategy Insights

Due to Thermy's high Magic/Ranged defence and typeless attacks, the primary strategies revolve around maximizing Melee DPS and mitigating the constant, rapid chip damage.

  1. Standard Melee:
    • Use your best Melee gear, prioritizing Strength bonus then Crush/Slash accuracy (depending on weapon). Arclight/Emberlight (demonbane weapons) are highly effective. Scythe of Vitur, Osmumten's Fang, Ghrazi Rapier, etc., are top choices.
    • Pray Piety (or Chivalry).
    • Focus on maximizing DPS to kill Thermy quickly before chip damage overwhelms your food supply. Bring high-healing food.
    • Walk-Under Method: Thermy attacks every 2 ticks, while most melee weapons attack every 4 ticks. Attack Thermy, immediately click underneath it, wait for your attack cooldown, step out, attack again, and immediately walk under again. This halves the damage you take but requires more attention. A more advanced version uses dropped items (like Ashes) to 'red-click' stall the boss while under it.
  2. Blood Barrage Healing (Magic - Slower/Sustainable):
    • Use Magic gear focused on damage % and wear Bloodbark Armour with an Ancient Sceptre (or better) to autocast Blood Barrage.
    • The healing from Blood Barrage (especially if hitting nearby Smoke Devils simultaneously) can potentially sustain your HP, allowing for longer trips with less food.
    • Much slower kills than Melee due to Thermy's high Magic Defence. Generally only used for very long trips or specific account builds.
  3. Redemption Method (Prayer Flicking):
    • Requires: 49 Prayer (for Redemption), high HP (90+ recommended), high Prayer level (for better healing).
    • Method: Allow Thermy to damage you until below 10% HP, triggering Redemption to heal you (heals 25% of Prayer level). Immediately drink a Prayer Potion/Super Restore and reactivate Redemption.
    • Notes: Saves significantly on food but requires constant attention to prayer points and HP. Very efficient in terms of supplies per kill for experienced players. Spectral Spirit Shield helps conserve prayer. Forgotten/Ancient Brews can be used for cheaper prayer restoration but lower Defence temporarily.
  4. POH/Nardah Method (Spec Dumping):
    • Use high-damage special attack weapons (Dragon Claws, Voidwaker, etc.). Dump specs, kill Thermy quickly, teleport to POH (pool) or use Desert Amulet 4 (Nardah) to restore stats/HP/Prayer/Spec, teleport back.
    • Slower kills/hr due to travel time but very low supply cost.
  • Melee (Recommended):
    • Weapon: Emberlight/Arclight (Stab/Slash) > Scythe (Crush) > Fang (Stab) > Rapier/Inq Mace/Saeldor > Whip/Hasta etc. Dragon Warhammer/BGS for spec.
    • Armour: Slayer Helmet (i) MANDATORY. Torva > Bandos > Inquisitor's (with Crush weapon) > Fighter Torso/Obsidian. Prioritize Strength bonus.
    • Other: Infernal Cape, Avernic Defender, Primordial Boots, Ferocious/Barrows Gloves, Ultor/Berserker Ring (i), Amulet of Torture.
    • Inventory: Divine Super Combat, Prayer Potions/Super Restores, High-healing food (Anglerfish, Karambwan), Emergency Teleport, Rune Pouch (optional, for Alchs/Thralls), Bonecrusher/Ash Sanctifier (optional).
  • Magic (Blood Barrage):
    • Weapon: Kodai > Nightmare Staff > Ancient Sceptre variants > Master Wand/Ancient Staff.
    • Armour: Ancestral > Virtus > Ahrim's / Bloodbark. Slayer Helmet (i).
    • Other: Occult, Tormented Bracelet, Imbued God Cape, Eternal Boots, Magus Ring (i).
    • Inventory: Runes for Blood Barrage, Prayer Potions, Emergency Teleport, High Alch runes, Bonecrusher/Ash Sanctifier.

Notable Drops

  • Uniques: Occult necklace (1/350), Smoke battlestaff (1/512), Dragon chainbody (1/2,000).
  • Tertiary: Jar of smoke (1/2,000), Pet smoke devil (1/3,000), Elite Clue Scroll (1/500), Hard Clue Scroll (1/96).
  • Other: Rune items (Dagger, Chainbody, Battleaxe, Scimitar), Mystic Staves (Air, Fire), Dragon Scimitar, Ancient Staff, various runes (Smoke, Soul, Air), Onyx Bolt Tips, Snapdragon Seeds.

(Drop rates are estimates based on the Wiki/Drop Rate Project data provided).

Conclusion

The Thermonuclear Smoke Devil offers a unique challenge with its rapid, typeless attacks and high defences against Magic and Ranged. Mastering Melee techniques like the walk-under method or the supply-saving Redemption strategy allows for efficient farming of its valuable uniques, particularly the Occult Necklace and Smoke Battlestaff. Remember your Slayer task and face mask!

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