Roach/Development

Roaches previously attacked air units but that ability 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.