- Thor: gains Mechanical Rebirth. Killing the Thor creates "Wreckage". This wreckage is immobile and has no attacks. However, the wreckage can activate Mechanical Rebirth and rebuild itself into a Thor at full health.
- Nullifier: Loses Null Void.
- Mothership: No longer unique.
- Carrier: Loses escorts.
- Queen: Loses the ability to create defensive structures. Gains the ability to transform a selected Larva into a Mutant Larva.
- Mutant Larva: larva that take up 1 supply, and can mutate into any unit. This costs the same resources as regular larva production, but is faster than regular production.
- Corruptors: require only a Lair to be built.
- Overlords: gain drop Creep.
- Overseers: lose Creep drop [? Again, they may never have had it]. They gain the ability to create a Changeling: a unit that can impersonate the basic unit of any other race.
Zerg Buildings and Mechanics:
- Swarm Clutches/Shriekers: cut
- Sunken/Spore Clusters: now called Spine/Spore Crawlers. They have less Hp when in mobile form.
- Hydralisk Den: requires a Lair.
- Nydus Worm: no longer a free-roaming unit. A Nydus Worm is now a building much like the Canal: it can be built on any patch of creep that you have vision over. With Overlord creep drop, this still allows greater mobility.
- Creep damages enemy buildings slowly.
- Zerg buildings not on creep take damage slowly.
- Gas Mechanic, v1.0: Geysers start with some quantity of gas, 600 at this point. Players can spend minerals (100) to get an additional quantity of gas (600). During this process, the geyser turns off for 45 seconds (workers can't get gas). Geysers that are empty still provide 2 gas.