Splitting Arrows is a skill that can be used by human characters.

Splitting Arrows Pic

Skill Text: "The splitting arrow has the magical property that it severs into different arrows after having been fired, so allowing the bowman to hit multiple targets at the same time. The more adept he becomes at the craft, the more separate projectiles the original arrow will split into."

Note: If you are holding a melee weapon, using a Ranger skill will instantly switch to an equipped ranged weapon.

Skill Level Number of Arrows Mana Cost Cooldown (seconds)
1 2 29 5
2 3 35 5
3 4 41 5
4 5 45 5
5 6 49 5
6 7 53 5
7 8 57 5
8 9 61 5
9 10 65 5
10 11 69 5
11 12 73 5
12 13 77 5
13 14 81 5
14 15 85 5
15 16 89 5


It may not be readily apparent early-on, with Splitting Arrow firing so few shots at once at smaller groups of smaller enemies, but Splitting Arrows has a "shotgun" effect.  Rather than a few arrows picking and chasing certain targets while the rest go off randomly and uselessly, the main target is chosen and all the extra arrows fly outward nearly randomly... yet any arrow that hits an enemy works as a single shot would have.  Rather than "allowing the bowman to hit multiple targets at the same time", it should really say "fires multiple arrows, all doing full damage to whatever they strike, even if the same enemy is hit by every arrow fired."  With the way gear scales in the expansion (and enemy health and defenses, especially on Nightmare Mode), Explosive Arrows' damage is quickly overtaken by even normal shots, and Splitting Arrows stacks just fine with Way of the Ranger, while Explosive Arrows does not.

Once your Way of the Ranger increases your damage by nearly 600% (on an expansion-level Unique bow already hitting for 800+) and your ranger's crit rate is in the 75-80% range, it doesn't take a genius to do the math.  Eventually the choice comes down to Explosive being guaranteed to hit a lot of enemies from really far away for a little damage (or what is a "little" in the expansion), or getting right up against a group of enemies and hitting 2-3 of them for 4-5,000 damage 4-5 times each. 

Explosive is great up until the end of the Flying Fortresses and you won't even want more power because because it's totally unnecessary, but its faults start to show with scaling issues later and Splitting is probably the better choice.