Diablo III- Skills Article CXXXII: The Wizard, Secondary Skills- Arcane Orb

Arcane Orb (35 Arcane Power): Launch an orb of energy in the target direction that explodes when it hits something, dealing 175% weapon damage as Arcane damage to all enemies in a 10 yard radius.

Arcane Orb is a vastly more useful skill for general purposes than Ray of Frost- while the damage is lower, particularly compared to the Arcane Power consumption, it affects an area and you don’t have to hold still and maintain it.  The explosion radius is nice, though not as big as you’re likely to find yourself wishing it was.  Because of its high cost, this skill really can’t be spammed or streamed even under the best of conditions, so get used to dealing your high damage in bursts if you use it.

Obliteration (35 Arcane Power): Launch an orb of energy in the target direction that explodes when it hits something, dealing 228% weapon damage as Arcane damage to all enemies in a 10 yard radius.

The first rune for Arcane Orb follows the Demon Hunter pattern of ‘And now I do it harder’ by considerably increasing the damage of the base skill.  228% damage is enough to kill or cripple most common enemies, so this is a fairly good choice of Secondary skill.

Arcane Orbit (35 Arcane Power): You spawn four Arcane Orbs that circle you until triggered.  When an enemy is in melee range of you, one orb will explode, to a maximum frequency of one orb per second.  Each orb deals 70% weapon damage as Arcane damage when it explodes.

Arcane Orbit completely changes Arcane Orb, converting it from an offensive skill to a defensive skill.  While not as effective as it could be, thanks to the slow rate at which the orbs trigger, Arcane Orbit serves as a nice source of additional damage- in this form, you want to trigger the skill between battles and shift to a more evasive playstyle when the orbs run out- you’re probably going to spend your Arcane Power on direct offense during combat, and you don’t need to be diverting it for this emergency defense.  It’s a bit sad that the damage is so low, but combining this with Spectral Blade can be fun.

Arcane Nova (35 Arcane Power): Launch an orb of energy in the target direction that explodes when it hits something, dealing 175% weapon damage as Arcane damage to all enemies in a 20 yard radius.

Increasing the radius of Arcane Orb serves one function, and it’s an obvious one- make it more effective against enemy groups.  A 20-yard radius is very big for a projectile attack like this, and with the damage Arcane Orb deals, it’s well worth the Arcane Power when you’re facing large numbers of demons.

Tap the Source (20 Arcane Power): Launch an orb of energy in the target direction that explodes when it hits something, dealing 175% weapon damage as Arcane damage to all enemies in a 10 yard radius.

If you like Arcane Orb as it is, then this is the rune you want.  Casting Arcane Orb more often can only mean more fun when you’re already satisfied with the skill, and comes close to actually making the attack spammable.  A very respectable rune, and one that can greatly enhance your combat- the lowered cost is small enough that you can essentially alternate Tap the Source with Electrocute, making you very effective at handling clusters of enemies without even involving your hotbar skills.

Celestial Orb (35 Arcane Power): Launch an orb of energy in the target direction that pierces all enemies and deals 175% weapon damage to all enemies it passes through.

Celestial Orb, despite minimally changing Arcane Orb’s appearance, has a drastic effect on what the skill actually does.  Most useful for slightly spread groups or enemies that have ranged allies behind them, Celestial Orb loses a lot in its area of effect by turning into something like a line of damage, so you have to weigh your choice and needs very carefully before applying this rune.  If it turns out to be the right rune for you, though, it creates a staggering improvement in the effectiveness of the skill.