Heart of the Swarm: Player Guide

StarCraft Zerg Overhaul for Stellaris 4.5 · Author: val · Discord: @valsey

The Swarm does not research. It evolves. This guide explains what the mod changes, the new terms you will meet, how Essence works, how to use Abathur’s Evolution Pits, how to spread creep, and how the story characters arrive. Spoilers are folded away in the last section.

Contents

1. What changes, at a glance
2. Glossary
3. Your first hour on Char
4. Essence
5. The Evolution tree
6. Evolution Pits
7. The fleet
8. Creep
9. Broods
10. Kerrigan and the council
11. Traditions and ascension perks
12. Infestation
13. Spoilers: Stukov, Dehaka and the primal path
14. Tips, troubleshooting and console commands

What changes, at a glance

You play The Swarm, a prescripted hive-mind empire. Pick it from the empire list; everything below is built into it.

Requires the Utopia and BioGenesis DLCs. English only. Achievements are disabled, as with any mod that changes game files.

Glossary

Your first hour on Char

You start on Char with Sarah Kerrigan on the throne, Abathur (scientist), Zagara (commander) and Izsha (official) on the council, 200 Essence, and a small brood of Mutalisks in orbit. There are no other leaders. Two strains are known from day one: Mutalisk (the corvette hull) and Overlord (+20 naval capacity).

A sensible opening:

1. Research. The Evolution category appears in the Society tab. Zergling and Guardian are offered in the first draw. Take Zergling first if you want armies early, Guardian if you want your Mutalisks to mature.
2. Spend your first Essence on the Mutalisk pit. The Mutalisk strain is known from the start, so “Evolution Pit: Mutalisk” is already on Char’s Decisions tab for 150 Essence. Sundering Glaive gives +10% weapon damage; Vicious gives +5% hull and armour regeneration. Choose and live with it.
3. Keep the Hydroponics Bay. The starbase starts with one in its only building slot. Keep it until you can afford a Starhold; the Swarm eats a lot.
4. Expand. Claim a neighbouring system as soon as your Overlord has surveyed it. Creep only spreads into systems you own.
5. Fight something. Space fauna and pirates near home are your first Essence income. Every kill pays.

Tip. Hover the strategic-resources group at the right of the top bar to see Essence, or open the Budget screen. It is listed under Exceptional Materials.

Essence

Essence (Zerg) is the resource the Swarm cannot mine, trade or build. It comes from consuming and it pays for growth.

Earning it

Only kills made by your own ships count. As a Devouring Swarm you purge every foreign pop you conquer automatically, so conquest is the steady income; war is the fast one.

Spending it

A Swarm that stops eating stops evolving.

The Evolution tree

Open the Research screen. Strains appear in the Society area under the Evolution category, which only the Swarm can see. Research them like any technology. The vanilla bio-ship hull techs never appear for the Swarm; each Sky strain hands you the matching hull the moment it completes.

Ground: the armies

Sky: the fleet

Deep: everything else

Order matters. Viper needs Mutalisk; Corruptor needs Viper; Brood Lord needs Corruptor; Leviathan needs both Nydus Network and Corruptor; Behemoth needs Leviathan and Brood Lord. Ground runs Zergling, then Roach or Baneling, then Hydralisk or Swarm Host, then Ultralisk.

Tip. Strains are drawn like normal technologies, so you will not always see the one you want. The Rapid Evolution tradition speeds biology research by 15%.

Evolution Pits

Ten strains open a pit: all six Ground strains plus Mutalisk, Viper, Corruptor and Brood Lord.

How to use one. Once the strain is researched, open Char, go to the Decisions tab and take “Evolution Pit: <strain>”. The decision costs Essence and takes a year to enact. When it completes, Abathur’s event opens with two sequences. Pick one. The mutation becomes a permanent empire modifier, the pit disappears from Char, and the other sequence is gone for good. Only a Primal Reversion brings it back.

You can see your mutations on the Government screen (the thin column of icons at the far left) and in any ship or army tooltip under Modifiers.

Ground pits

Sky pits

Choosing. Ground pits split between attack (A) and economy or defence (B). Sky pits split between damage and durability. A Swarm that plans to bombard and invade wants Raptor, Vile and Impaler; one that holds a chokepoint wants Lurker, Torrasque and Corruption. There is no wrong answer, only a permanent one, unless you go primal.

The fleet

Every hull is a Zerg creature from StarCraft II, animated. Bio-ship rules apply: hulls are grown, cost food upkeep, and pass through Juvenile, Mature and Elder growth stages.

Living hulls. The Heart of the Swarm civic sets shields to -75%, hull to +15%, and adds 5% hull and armour regeneration. Build for armour and hull, not shields, and let damaged broods sit a month to knit back together. Kerrigan’s own trait adds fire rate and regeneration on any fleet she commands.

Designs. Auto-generated designs work. If you design by hand, remember the empty shield slots are a feature: fill utility slots with armour and regenerative components.

Creep

Creep is the Swarm’s territory made visible, in two buildings.

Creep Tumor is a planet building (Infrastructure tab, government category, 200 minerals and 25 Essence, one per planet). On that planet: pop growth +10%, building speed +10%, defending armies +25% health and +10% damage, and orbital bombardment damage -25%.

Creep Colony is a starbase building (75 alloys and 25 Essence, needs a free building slot, so a Starport must give up its Hydroponics Bay or be upgraded to a Starhold). On its own system: pop growth +5%, army build speed +25%, and the station regenerates 10% hull and armour. Then, every month, it pushes creep into every neighbouring system the Swarm owns.

How the spread works

• Only systems where your starbase is the space owner receive creep. Claim your neighbours first.
• The check runs on the monthly tick. The first time creep crosses into a new system you get a short notice; after that it is silent.
• A creeped system shows a Creep modifier in its tooltip and in the system view: pop growth +5% and army build speed +15% for every planet there.
• Lose a system and the creep burns off within the month.

A Creep Colony at each frontier starbase covers a whole border in a few months. The Creep Spread tradition adds pop growth and building speed on top.

Broods

Every Swarm commander is a broodmother in waiting. When a commander levels up, one of four brood traits can be picked. One per commander, and they exclude each other.

Losing a broodmother. When a commander dies, “A Broodmother Falls” fires and regrowing the brood costs 25 Essence. Keep your commanders out of losing fights, or keep Essence in reserve.

Kerrigan and the council

Sarah Kerrigan is your ruler and does not die of age. She is a commander with a Queen of Blades destiny trait that grows through four tiers, and her portrait changes as she ascends.

The council. Abathur (scientist, Evolution Master) drives research and the pits. Zagara (commander, First Broodmother) leads armies and fleets. Izsha (official, Memory of the Swarm) runs the empire. All three are immortal to old age; combat and events can still kill them. Recruited leaders are ordinary broods with Overseer, Zergling or Hydralisk portraits.

Traditions and ascension perks

The Swarm tradition tree is the Swarm’s own.

Two ascension perks are the Swarm’s alone:

• Heart of the Swarm: army damage +15%, fleet fire rate +5%; Kerrigan reaches tier III and her final tier becomes possible.
• Primal Evolution: adds the primal option to every Evolution Pit and unlocks Primal Reversion. See the spoiler section for how it is earned.

Infestation

Conquer a planet with foreign pops, open it, and take the Infest Population decision (50 Essence, six months). Every non-Zerg pop on the world becomes Infested: a hive-minded Zerg species that is part of the Swarm at last, instead of being purged. The decision refunds 30 Essence when it completes.

Infesting keeps the workforce a purge would eat. The trade-off is Essence: a purge pays 15 per pop group, infestation pays 30 once. Use it on big, valuable worlds and let the Devouring Swarm handle the rest.

Spoilers: Stukov, Dehaka and the primal path

Tips, troubleshooting and console commands

Where is Essence? Hover the strategic-resources group at the right of the top bar (Exceptional Materials), or open the Budget screen. It never appears in planet output because planets do not produce it.

A pit is not showing. Pits only appear on Char (the capital) and only once the strain is researched. A pit you have used stays hidden until a Primal Reversion.

Creep is not spreading. The Creep Colony must be finished (240 days), and the neighbouring system must be owned by you, not merely surveyed. Wait for the monthly tick.

⚠️ Saves from before version 0.1.2 started Char without its rural districts and deposits. Run event zerg.3 once in the console to repair the planet, then run this once to bring it up to the current starting set:

effect capital_scope = { add_district = { district_type = district_generator ignore_cap = yes } add_district = { district_type = district_farming ignore_cap = yes } }

Console cheat sheet

Open the console with the key above Tab. These are useful for trying things out.

Achievements are disabled by the mod, so the console costs you nothing.

StarCraft, the Zerg, Kerrigan and all related characters are the property of Blizzard Entertainment. This is a non-commercial fan work.