This rune effect fires three darts in rapid succession, each of which can hit the same target, or different targets. The damage is cut to 60% per dart, from 100% at the base skill, but since all three can hit the target, the total damage is considerably higher.
The instant an enemy takes enough damage to die additional darts will pass through it, so even though they are very close together and very fast, if the first or second dart kills, the next dart or two will pass on, potentially striking another target.
Earlier in development, each level of the Indigo rune added another shot, up to a maximum of 8 in machine gun speed. This effect was lowered to a maximum of 3 darts, though the damage of each was raised to compensate for function, if not coolness.
Prior to the skill revision in February 2012, this rune effect was enabled by the Indigo Rune, granting the following effect with a level 7 runestone.