Twisted bow

The Twisted bow is a reward from the Chambers of Xeric that requires a Ranged level of 75 to wield. It can fire any type of arrow, including dragon arrows. The Twisted bow is extremely valuable due to its unmatched power against bosses with a high magic level, such as Dagannoth Prime.

Passive effect
Unlike other bows that have a set strength, the twisted bow functions differently: the higher the target's Magic level is, the higher the bow's accuracy and damage.

The accuracy modifier is $$140 + \frac{3 Magic - 10}{100} - \frac{(\frac{3 Magic}{10} - 100) ^2}{100}$$, with the cap at 140.

The damage modifier is $$250 + \frac{3 Magic - 14}{100} - \frac{(\frac{3 Magic}{10} - 140) ^2}{100}$$, with the cap at 250 outside the Chambers of Xeric, and 350 within.

The following graph shows the buff % at different Magic levels, with the damage capped at level 250 (excluding NPCs found within the Chambers of Xeric):

Therefore, the maximum hit with the twisted bow outside of the Chambers of Xeric is 83 with Dragon arrows and 99 Ranged, when using all damage boosting items and effects (Ranging potion, Rigour, Necklace of anguish, and imbued Slayer helmet).

The twisted bow is commonly used against bosses and strong monsters that use highly accurate and powerful magic attacks, such as Commander Zilyana, Brutal black dragons, Chaos Elemental, or the mages and Jads in Inferno and Fight Caves. In addition, some bosses have exceptionally high magic levels despite not using it as a combat style, so it is just as deadly against them.

However, against monsters that have a lower magic level, the twisted bow's damage and accuracy outputs become very unstable, with its damage output being significantly worse than a toxic blowpipe. This also applies to other players in PvP situations.

Trivia

 * The Twisted bow used to have a damage modifier cap of 350, though it was capped to 250 on 19 January 2017 due to it dealing massive damage against bosses such as Commander Zilyana.
 * As a result of the twisted bow's introduction, General Graardor's magic level and magic defence bonus were adjusted as the bow originally outperformed other high-end weapons against him.
 * The Twisted bow is similar in function to the Hexhunter bow in RuneScape 3.