ranged weapon
Target: one creature or two creatures
Attack: Dexterity vs. AC, separate attacks per target
If two creatures are targeted, each attack roll takes a −2 penalty.
Hit: 1[W] + Dexterity modifier damage. If only one creature was targeted, the damage roll gains a +2 bonus.
Rapid volley is a 1st-level ranger encounter attack power. It is a Dexterity-based ranged weapon attack that can either target one creature with a damage bonus, or target two creatures with a penalty to both attack rolls.[MP:43]
This power is claimed to be overshadowed by two-fanged strike[1]. This can be debated, as rapid volley can technically do more average damage on a single target by a small amount, and two-fanged strike can't target more than one creature. However, rapid volley's multi-target effect is outclassed by rapid shot, an at-will that can potentially target more creatures with the same accuracy penalty and the same amount of damage.