The Zerg Regeneration mechanic is a permanent, passive attribute of all Zerg units and buildings. It allows an injured Zerg unit or structure to fully regenerate its health. Once damage is done to a Zerg unit, it begins to regenerate health, unlike Protoss Plasma Shields, which require 10 seconds of no combat activity.
- Health regenerates at a rate of 0.27 points per game second.
- Zerg units and structures begin to regenerate health the instant damage is taken.
- The instant start to regeneration allows Zerg units and structures to survive spells that would otherwise kill it.
In Combination with Spells
- Roaches regenerate health at an accelerated rate (5 Hit Points per second) while Burrowed, due to Rapid Regeneration.
- Roach regeneration rate can be further increased (to 10 HP/s) after the Tunneling Claws upgrade is researched.
- Mutalisks regenerate health faster (1 Hit Point per second) due to Tissue Regeneration.
- Units don't regenerate health at an increased rate when on Creep, a possible misconception during and prior to the StarCraft II beta.
- Zerg regeneration of structures continues even when the structure is not supported by creep. The structure loses health at a net rate of 2.73 health per second, linearly (the combination of 3 hps loss and 0.27 hps regeneration).
http://sc2armory.com/game/zerg for generic regeneration amount of 0.27 hps (the same for all units/structures).