Flare

From The StarCraft 2 Wiki

The Medic ability Flare is used in StarCraft II for lighting up an are on the battlefield.

[edit] Background

This skill, Flare, is available to the Terran Medics in Starcraft II and performs the original intended purpose of the A-13 Flash Grenade Launcher, before it was modified to launch Optical Flares.

It temporarily illuminates a portion of the battlefield, allowing a glimpse into uncharted territory or providing a "spotter" to high ground.

[edit] Development

It's worth noting that the Flare ability of the Medic is not available in normal StarCraft II multiplayer, since the Medic is no a cancelled unit.