Borrowed Power

Borrowed Power is a spell in the Lunar Spellbook, that was released on 23 August 2011, along with many other new minigame rewards. It can be unlocked by speaking to Pauline for 850,000 Produce Points, obtained from playing Livid Farm. With this spell, you have the ability to cast selected spells from the standard spellbook while wearing an Arcane capacitor necklace charged with the runes for those spells. Level 99 Magic is required to cast this spell.

The spell allows you to cast the following spells:

In order to use the Borrowed Power spell, you must first charge your arcane capacitor necklace. You will need 1,000 times the normal runes required for that spell, resulting in 1,000 charges of that spell on your arcane capacitor necklace. It is important to be sure of what spell one wants to charge the necklace with, as only one spell's runes may be used to charge the necklace. One cannot access more than one of Borrowed Power's spells, as one cannot own more than one necklace at a given time. Casting the spell then requires 3 astral runes and 1 charge from your arcane capacitor necklace. Autocast is not available. The necklace needs to be worn to be effective. Upon using up your last charge on your necklace, you get a message saying "Your amulet of power has run out of charge and has crumbled to dust. You will need to get another one from Pauline to continue using Borrowed Power" and you will lose your capacator, which many say makes the spell less worth using.

Trivia

 * This is currently the only spell that needs 99 Magic, and is the highest requirement for a spell.
 * Attempting to cast High Alchemy with the Explorer's ring 4, wearing the Arcane Capacator set to High Alchemy, will cause a "You don't have enough astral runes" message to appear. It does nothing and no charges from the Capacator or Astral Runes will be lost when High Alchemy is cast from the ring.
 * You used to be able to cast High Alchemy on three astral runes to consume one astral rune and no charges. This was patched on May 22.
 * This spell is rather unpopular as many believe the spell selection was underpowered and useless. It takes quite some time to achieve the spell, costs three extra astral runes and the necklace must be worn while casting Borrowed Power, making it impossible to wear other necklaces which give better magic combat boosts such as the Arcane stream necklace.
 * With the release of the Evolution of Combat, Borrowed power now requires an Armadyl Rune as well as the Lunar Runes and the Arcane Capacator.