Channeling

Version 0.30: This article may not be up to date for the latest stable release of Crawl.

For spells like Searing Ray with an effect that requires several turns of focus, see Channeling spell.

Dramatically increases the user's regeneration of magical power for a duration that increases with Invocations skill.

Channeling is the act of passively restoring MP to a character, as opposed to using a single-turn action like the Sublimation of Blood spell to restore MP. There are two types: Active Channeling (which require the use of an activated ability), and Passive Channeling (which comes from equipment and happens without the player's input).

Djinn do not use MP and cannot make use of any form of channeling.

Active Channeling

Channel Magic is an ability that allows worshipers of Sif Muna to restore MP much more quickly. Followers gain this ability at 1* piety.

Success rate: (60 + 4*Invocations)/100 + Piety/25
MP Recovered: 3-5 per turn for (3 + 2d(2/3 * Invocations)/2) turns, average (3 + Invocations/3) turns

Passive Channeling

Orbs of energy and the crystal ball of Wucad Mu allow you to passively channel energy, refunding the MP costs of spells you cast.

With the energy ego, when you successfully cast a spell, there's a 20% chance to have the full MP cost refunded. When you miscast a spell, you will always have MP refunded. However, it increases your raw spell failure chance by +10%. The crystal ball of Wucad Mu has double the refund rate, with the same failure penalty. (For reference, the first stack of wizardry reduces raw spell failure by 25%.)

Note that this does not mean that your spell failure actually increases by +10%, as its modified by a function. See the Spell Success page for details. For example:

• If you have a spell with 6% failure, an orb of energy increases it to 17% actual failure.
• If you have a spell with 2% failure, an orb of energy increases it to 8% actual failure.
• For spells with 1% failure, it varies. A 1% failure might increase to 2% or 9% actual failure, depending on how much skill you have

History

• In 0.30, passive channeling was reworked. Prior to this version, you had a Sources * Evocations / 108 (orb of energy: 2 sources ; staff of Wucad Mu: 3) to succeed. If you succeeded, you had a 1 / (Evocations - MP cost) to backfire, either draining 1-5 points of intelligence or inflicting confusion. As Wucad Mu is now an orb, you are physically unable to stack channeling.
• In 0.28, the ability to stack multiple sources of passive channeling was added, along with the orb of energy. Success rate per source decreased, but all items count towards multiple sources.
• Prior to 0.27, the staff of Wucad Mu's success rate was Evocations / 81 (buffed to Evocations / 54), and backfiring did not refund MP.
• Prior to 0.26, you could actively channel magic by evoking a staff of energy; compared to other active channeling items, this provided fewer MP but could not backfire. The staff of Wucad Mu could also channel magic in this way.
• Prior to 0.25, a crystal ball of energy could be used as a high-risk way to restore MP, much like the staff of Wucad Mu.
• Prior to 0.24, Channel Magic was Sif Muna's *** ability.
• Prior to 0.19, Sif Muna instead granted Channel Energy, which was a repeatably usable ability, not a duration. With each use, it restored a small amount of MP (depending on Invocations skill) and cost hunger but no piety.