Sidearm is a rune effect in Frenzy, a Fury-generating Barbarian skill.
This rune effect has a 25% chance to throw an axe at a nearby enemy. The axe pierces all enemies in the path and deals 110% weapon damage. This effect is visually-interesting, as high speed hatchets go flying off in all directions, somewhat like the daggers hurled by the Demon Hunter's Action Shot rune effect in Vault.
It's a nice skill improvement in the early going, but the axes aren't frequent, damaging, or controllable enough to make it a major strategic component of any long term Barbarian build. The axes can be quite useful when using Frenzy against large groups though, as the axes pierce and if enemies are clustered together, the axe can strike numerous targets.
Skill Rune Effects
See the Frenzy rune effects article for thorough descriptions of all the rune effects in Frenzy, including screenshots, videos, and strategy tips.
|| Generate: 4 Fury per attack|
Swing for 220% weapon damage. Frenzy's attack speed increases by 15% for 4 seconds with each swing. This effect stacks up to 5 times.
|| Each strike has a 25% chance to throw a piercing axe at a nearby enemy that deals 300% weapon damage as Cold to all enemies in its path.|
Frenzy's damage turns into Cold.
Screenshots and videos will be added post-release.
Prior to the February 2012 skill and rune system overhaul, this effect was created by the Indigo Rune, which granted the following effect:
Each strike has a 55% chance to throw a piercing axe at a nearby enemy that deals 100% weapon damage to all enemies in its path.