Arclight

“The magical sword 'Silverlight', enhanced with the blood of Agrith-Naar and ancient shards.”

Arclight is a demonbane slash sword that requires 75 Attack to wield. An upgraded version of Darklight, it gives a huge 70% accuracy and damage bonus against demons, which makes it one of the best-value weapons in the game for demon Slayer tasks and bosses like K'ril Tsutsaroth and demonic gorillas. It is made at the Catacombs of Kourend altar and can later be upgraded into Emberlight.

Equipment bonuses

Charged, Arclight has +38 slash attack and +8 strength — modest on paper, but the 70% demonbane bonus means that against demons it can out-damage far pricier weapons like the Blade of Saeldor or Scythe of Vitur.

Attack bonuses
+10
+38
0
0
0
Defence bonuses
0
+3
+2
+2
0
Other bonuses
+8
+0
+0%
+0
Slot
Weapon

Requires 75 Attack · slash sword · attack speed 4 (charged) · consumes 1 charge per hit · reverts to an inactive Darklight-equivalent when empty.

Arclight against demons

Against demonic monsters Arclight adds a flat 70% accuracy and damage boost — one of the largest demonbane effects in the game. It also counts as a silver weapon, so it can hurt tier-2 vampyres and gets +10% against tier-1 vampyres. The one exception is Duke Sucellus, whose 30% demonbane resistance drops the bonus to 49%. Compare it against your other options in the OSRS DPS calculator.

Charges and upgrading to Emberlight

Arclight starts with 1,000 charges and gains 333 per ancient shard (or 1,000 if you add three at once), up to a maximum of 10,000 charges (30 shards). It uses one charge per successful hit and reverts to an inactive form when empty. Every charge spent also builds infusion, and once you have read Duradel's notes you can combine a tormented synapse with a fully charged or infused Arclight at an anvil (74 Smithing) to forge Emberlight, which no longer degrades.

Special attack — Weaken

Arclight keeps Darklight's Weaken special (50% energy), which lowers the target's Strength, Attack and Defence by 5% + 1 — or 10% + 1 against demons. It stacks additively, so two specials on a demon drop those stats by 20% + 2, making bosses much easier to hit and survive.

How to get Arclight

First get Darklight from the Shadow of the Storm quest (or reclaim it from Sir Prysin for 1,000 coins), then use it on the altar in the centre of the Catacombs of Kourend with three ancient shards in your inventory. Ancient shards come from Slayer tasks in the Catacombs. Arclight is untradeable.

Arclight FAQ

What Attack level do you need for Arclight?
You need 75 Attack to wield Arclight.
How do you get Arclight?
Use Darklight (from the Shadow of the Storm quest) on the altar in the centre of the Catacombs of Kourend with three ancient shards in your inventory.
How much better is Arclight against demons?
It adds a 70% accuracy and damage bonus against demons — so it can out-damage far more expensive weapons on demon tasks and bosses.
How many charges does Arclight have?
Up to 10,000 charges (30 ancient shards), used one per hit. When empty it reverts to an inactive form, keeping its infusion progress.
Should I upgrade Arclight to Emberlight?
If you fight demons often, yes. Emberlight keeps the 70% bonus, has much higher stats, doesn't degrade and has a stronger special — made with a tormented synapse at 74 Smithing.

Update history

23 October 2024Depleting Arclight's charges now leaves an inactive variant that keeps infusion progress, instead of reverting to Darklight; single ancient shards can now be added for 333 charges.
10 July 2024Spent charges now build "infusion" toward upgrading into Emberlight (While Guthix Sleeps).
23 February 2017Arclight can no longer be alchemised.

Source: OSRS Wiki — Arclight (Changes).