Roach

The Roach is a zerg ground unit in StarCraft II.

Overview
The Roach is a particularly tough Zerg breed due to its high speed regeneration ability.

It evolved from the quickly-healing zantar slug of Garrxax. Its ranged Acid Saliva attack is capable of penetrating neosteel and comes from the same core species.

Game Unit
Roaches are strong against Hellions, Zealots, and Zerglings, and weak against MMM, Immortals and Ultralisks. They have no anti-air attack. Roaches inherit the medium attacker and ambusher role from the original StarCraft's Hydralisk and Lurker, respectively.

Attacks
The Roach is a ranged unit, giving it added utility at choke points. The Roach rises slightly when it attacks. It also has a melee attack that it, like the Hydralisk, performs at close range for the same damage as the ranged attack.

Zerg vs Terran
A Roach/Baneling combo is very powerful against Terrans, as the Roaches will soak damage, enabling the Banelings to get close to the enemy and deal their high damage attacks.

Zerg vs Zerg
Roaches and Zerglings are used early in Zerg vs Zerg matches. Compared to Zerglings, Roaches are a more defensive unit. Cost for cost, Roaches win against Zerglings at chokepoints but lose in open areas. Later in the game, numerous Roaches can defeat numerous Zerglings even in open areas.

As a game progresses, a Roach/Hydralisk combo can defeat a Zergling/Mutalisk combo.

Zerg vs Protoss
italic(awaiting strategies)

Development
Roaches previously attacked air units but that was removed from the game pre-retail release.

As of May 2008, due to a bug roaches were not affected by the Dark Swarm's secondary ability of preventing units inside it from firing. Dark Swarm was later removed from the game by October of that year.

Regeneration
In April 2008 the roach regenerated at 15 HP per second (25 hp/second with Organic Carapace). A roach could heal fast enough to retain approximately 50% of its hit points if hit by a psi storm, and over 80% of its hit points after its regeneration has been upgraded. The roach's regeneration rate appears to have slowed as of April 2009.

Blizzard removed the above-ground regeneration ability, as they felt it was too "random"; roaches could win or lose battles depending on how they were randomly targeted when opposing units attack-moved against them.

In June 2010, the Organic Carapace upgrade was removed.