The zerg greater spire is evolved from the spire (if there is a hive present somewhere in the same command structure) and it produces the genetic code that allows some zerg air breeds to mutate into different forms.^[1]

Contents 1 Game Structure 1.1 StarCraft 1.1.1 Researched Upgrades 1.2 StarCraft II 1.2.1 Researched Upgrades 1.2.2 Development 2 References

Game StructureEdit

StarCraftEdit

Greater Spire
Structure
Race	Zerg
Production
Minerals	100
Gas	150
Build time	120
Evolves from	Spire
Requires	Hive
Protection
Hit points	1000
Armor	1
Function
Allows	Mutalisk Scourge Guardian Devourer (BW Only)
Research	Flyer Attacks Flyer Carapace

The greater spire enables mutalisks to mutate into guardians and devourers. It also provides the same upgrades as the spire and will retain the evolutionary progress so that any aerial units keep all upgrades that were completed at the spire.

Researched UpgradesEdit

Flyer Attacks
Evolved at	Spire Greater spire
Hotkey	A
Properties
Level Level 1 Level 2 Level 3 Minerals 100 175 250 Gas 100 175 250 Evolution time 266 298 330 Required Lair Hive
Notes
+1 bonus to attack per level for mutalisks +2 bonus to attack per level for guardians and devourers.

Flyer Carapace
Evolved at	Spire Greater spire
Hotkey	C
Properties
Level Level 1 Level 2 Level 3 Minerals 150 225 300 Gas 150 225 300 Evolution time 266 298 330 Required Lair Hive
Notes
+1 bonus to armor per level for overlords, mutalisks, guardians, devourers, scourge and queen.

StarCraft IIEdit

Greater Spire
Structure
Race	Zerg
Properties
Broodlings produced	6
Production
Minerals	100
Gas	150
Build time	100
Evolves from	Spire
Requires	Hive
Hotkey	G
Protection
Hit points	1000
Armor	1
Type	Armored Biological Structure
Function
Allows	Mutalisk Corruptor Brood lord
Research	See below

In StarCraft II the greater spire enables production of the brood lord.

Researched UpgradesEdit

Flyer Attacks
Evolved at	Spire Greater spire
Properties
Level Level 1 Level 2 Level 3 Minerals 100 175 250 Gas 100 175 250 Evolution time 160 190 220 Required Lair Hive
Notes
Increases attack damage of mutalisks, corruptors, and brood lords.
Edit

Flyer Carapace
Evolved at	Spire Greater spire
Properties
Level Level 1 Level 2 Level 3 Minerals 150 225 300 Gas 150 225 300 Evolution time 160 190 220 Required Lair Hive
Notes
+1 bonus to armor per level for zerg air units.
Edit

DevelopmentEdit

The greater spire went through several revisions, essentially lingering in development hell. The initial designs were updates of the StarCraft I artwork which didn't seem to work. The shapes of the SC1 greater spire design didn't look good in 3D, as it was too bulky and the numerous pieces were too busy. Conveying the height the designers wanted was also a problem, since there were height limitations on tall buildings. When the development team started using Zbrush to create unit portraits some zerg buildings were also redesigned to take advantage of the more organic sculpting process.

The revision of the greater spire made progress towards the final in-game design but the building still looked out of place compared to the rest of the zerg structures. The final unification pass finally solved many of these problems. The lower portion of the spire was reused and slightly modified with additional armor. The top portion was replaced with the new greater spire design and retextured, finally completing the long process of updating the first game's design.^[2]

ReferencesEdit

Zerg Units and Structures of StarCraft/Brood War
Ground units	Larva · Drone · Zergling · Hydralisk · Lurker(BW) · Defiler · Ultralisk
Air units	Overlord · Mutalisk · Guardian · Scourge · Queen • Devourer(BW)
Infestation units	Broodling · Infested terran
Transition units	Egg · Lurker egg · Cocoon
Basic buildings	Hatchery · Extractor · Evolution chamber · Spawning pool · Creep colony · Spore colony · Sunken colony · Hydralisk den
Advanced buildings	Lair · Hive · Spire · Greater spire · Queen's nest · Nydus canal · Defiler mound · Ultralisk cavern · Infested command center
Other	Creep
Scrapped	Mutation chamber · Nydus pit

Zerg Units and Structures of StarCraft II
Land units	Larva · Drone · Zergling · Baneling · Roach · Hydralisk · Infestor · Ultralisk · Queen · Swarm host (HotS)
Air units	Overlord · Overseer · Mutalisk · Brood lord · Corruptor · Viper (HotS)
Spawned units	Broodling · Changeling (WoL) · Infested terran · Locust (HotS)
Basic buildings	Hatchery · Creep tumor · Extractor · Evolution chamber · Spawning pool · Baneling nest · Roach warren
Combat Buildings	Spine crawler · Spore crawler
Advanced buildings	Lair · Hive · Infestation pit · Spire · Greater spire · Hydralisk den · Nydus network · Nydus worm · Ultralisk cavern
Transition units	Egg · Baneling cocoon · Brood lord cocoon · Infested swarm egg · Overseer cocoon
Others	Creep
Campaign-Exclusive Units	Ground units Aberration · Brutalisk · Infested colonist · Infested marine · Omegalisk · Pygalisk · Pygalisk cocoon · Swarmling Air units Leviathan · Sac · Scourge · Swarm guardian Variant units Zergling (Raptor · Swarmling) · Baneling (Gorgeling · Splitterling) · Roach (Leech · Prowler)
Campaign-Exclusive Structures	Infested terran buildings (infested bunker · infested command center) · Spore cannon · Virophage
Canceled Zerg Units and Structures of StarCraft II

Zerg Breeds
Command Strains	Cerebrate · Metamorph · Overlord · Overmind · Queen, original · Queen, new variant (brood mother) · Queen of Blades
Core Strains	Ground Larva · Feederling · Drone · Queen · Zergling · Baneling · Roach · Hydralisk · Lurker · Defiler · Swarm host · Infestor · Nydus worm · Ultralisk · Brutalisk Aerospace Overlord · Overseer · Mutalisk · Guardian · Scourge · Queen · Devourer · Corruptor · Brood lord · Leviathan · Behemoth
Specialist Strains	Ground Zergling (Devouring One · Goblin · Raptor · Screamer · Swarmling · War Zergling) · Baneling (Gorgeling · Kaboomer · Splitterling) · Roach (Leech · Prowler) · Hydralisk (Hunter Killer · Hydolysk · Warg) · Queen (Brood mother · Char Queen) · Infestor (Choker) · Ultralisk (Blade Guardian · Juggernaut · Omegalisk · Pygalisk · Stank · Torrasque) · Brutalisk (Hunterling) · Nydus worm (Left 2 Die Nydus worm) Aerospace Overlord (Brain spectre · Mastermind · Yggdrasill) · Overseer (Spotter) · Mutalisk/Guardian (Drake · Evolved Mutalisk · Gargoyle · Kukulza · Feral Guardian) · Queen (Hand Maiden · Empress · Eschutriarch · Matriarch · Siren)
Spawned/Other	Broodling (Swarmling) · Changeling · Creep · Infested protoss · Locust · Parasite · Probe · Roverlisk · Sac · Swarm
Infested terrans	Aberration · Infested colonist · Infested marine · Explosive · Infestor-spawned · Mutate
Structures	Basic Hatchery · Creep tumor · Extractor · Evolution chamber · Spawning pool · Baneling nest · Eye · Creep colony · Spore colony · Sunken colony · Spine crawler · Spore crawler · Spore cannon · Hydralisk den Advanced Lair · Hive · Infestation pit · Spire · Greater spire · Queen's nest · Nydus canal · Nydus network · Defiler mound · Ultralisk cavern · Infested terran buildings (Infested command center · Infested bunker) · Virophage