Diablo III- Skills Article CIL: The Wizard, Mastery Skills- Explosive Blast

Explosive Blast (20 Arcane Power, Cooldown 6 Seconds): You drop a mass of energy at your feet.  After 1.5 seconds, this energy explodes, dealing 225% weapon damage as Physical damage to all enemies within 12 yards.

A bizarre skill specialized for Wizards who either dart into and out of or stick around in close-combat situations, Explosive Blast has a delay that is considerably more dangerous than that of the Meteor skill, because you have to stand where you want it to hit.  The damage is more than respectable, and the cost is light- but the cooldown keeps it unspammable, and the delay makes it not just hazardous but difficult to accurately use, despite the fairly large area of effect.  When considering Explosive Blast, you have to decide- are you going to stick with it even though it’s hard, and teach yourself how to best use it, or are you going to move on to something else where you can start at a level of proficiency higher than ‘clumsy’?

Unleashed (10 Arcane Power, Cooldown 6 Seconds): You drop a mass of energy at your feet.  After 1.5 seconds, this energy explodes, dealing 225% weapon damage as Physical damage to all enemies within 12 yards.

A reduction in cost.  Not a big worry with Explosive Blast, considering the length of the cooldown, but understandable if you want to use the skill for emergency situations- just get very good at predicting them, since they often happen too quickly for the skill to have time to actually explode.

Time Bomb (20 Arcane Power, Cooldown 6 Seconds): You drop a mass of energy at your feet.  After 2.5 seconds, this energy explodes, dealing 293% weapon damage as Physical damage to all enemies within 12 yards.

Time Bomb’s increased wait makes it far harder to use than Explosive Blast, forcing you to use it pretty much only with slowing and immobilizing effects.  The increased damage isn’t bad, but it’s not really high enough to warrant the huge increase in delay.

Short Fuse (20 Arcane Power, Cooldown 6 Seconds): You drop a mass of energy at your feet that immediately explodes, dealing 225% weapon damage as Physical damage to all enemies within 12 yards.

Probably the most useful form of Explosive Blast, Short Fuse removes the wait entirely.  This makes it infinitely easier to use the skill, though the cooldown keeps it from being a good source of regular damage.  Using it to soften up a batch of enemies can help a close-range Wizard, where a long-range Wizard will like to use this to splatter smaller enemies that they haven’t got time to focus their main damage spells on.

Obliterate (20 Arcane Power, Cooldown 6 Seconds): You drop a mass of energy at your feet.  After 1.5 seconds, this energy explodes, dealing 225% weapon damage as Physical damage to all enemies within 18 yards.

If the only problem you have with Explosive Blast is that you tend to slightly miss your targets, or if you just need an increased area of effect really badly, Obliterate can be useful.  It’s a bit unfortunate that it doesn’t do anything about the cooldown or delay on the spell, but at least the overall effectiveness still increases with this rune.

Chain Reaction (20 Arcane Power, Cooldown 6 Seconds): You drop three masses of energy, each a short time after the other.  After 1.5 seconds, each batch of energy explodes, dealing 97% weapon damage as Physical damage to all enemies within 12 yards.

Chain Reaction’s main point is that you can use it while moving, and thus spread a set of explosives to deal smaller damage in a larger and more shapeable area.  This gets especially nasty where the areas overlap, totaling only a tiny bit less damage than Time Bomb if all three explosions affect the same target.  For all that it’s more malleable than any other form of Explosive Blast, it is also a lot harder to use, since you have to pay attention to how quickly the ‘bombs’ drop and exactly how far apart they are.  Not a skill for people who don’t want to invest a lot of thought in what they’re doing with it.