Hostile Scaling

A Satisfactory mod (SML 3.12+, game version ≥ 491125 / Satisfactory 1.1) that scales hostile creature health, damage, and spawn frequency as you progress through milestone tiers. Everything is user-configurable through the in-game Mod Config menu.

How it works

System	Mechanism
Health	Hostile creatures get real scaled health: max health is set to vanilla class default × multiplier (current health percentage preserved), applied instantly on spawn via an AFGCreature::BeginPlay hook and reconciled every 10s for live creatures on tier-ups. Computing from the class default makes it idempotent — values never compound across saves. Health-display mods show the true scaled numbers.
Damage	Damage dealt by hostile creatures is multiplied. Hostile = any AFGCreature that is neither passive nor tamed (doggos and ambient fauna untouched), checked per instance so it works for every creature blueprint. By default only damage to players is scaled; a config toggle extends it to buildings/vehicles.
Damage paths	All three UFGHealthComponent entry points are hooked (TakeDamage, TakePointDamage, TakeRadialDamage) so melee, projectile/hitscan, and explosion damage are all covered.
Spawn frequency	The subsystem divides each hostile spawner's respawn time (in in-game days) by the multiplier, and optionally grows that spawner's spawn list so more creatures appear per location. A spawner counts as hostile when its creature class's default object is not passive — passive spawners (doggos, ambient fauna) are left at vanilla respawn time, and their pack size is returned to the size the mod recorded the first time it saw the spawner.
Keep respawning	Vanilla suppresses spawners near your base and eventually stops repopulating cleared areas, so the world empties out as you build. With Respawn Near Factories on (default), the mod bypasses near-base suppression on hostile spawners, re-arms their cleared packs on their normal (already-scaled) respawn schedule, and — if such a spawner can't find a valid spot (e.g. you floored over it) — gradually widens its search radius so creatures reappear nearby. Passive spawners keep vanilla near-base suppression. Toggle it off for vanilla behavior everywhere.
Tier progression	Highest unlocked milestone tier is read from the schematic manager. Each multiplier = Base + PerTier × Tier, clamped to [0.1, Max].

Original spawner values are stored in the savegame (keyed by spawner path), so scaling is always recomputed from vanilla numbers — it never compounds across sessions, and lowering the config later actually lowers the result. All logic is server-side, so multiplayer works with the mod installed on the host/server.

Default configuration

With defaults (PerTier 0.15/0.15/0.10), at tier 9 hostiles have ~2.35× health, deal ~2.35× damage, and spawners refill ~1.9× faster. Respawn Near Factories is on by default; Verbose Respawn Logging (a debugging aid that writes per-spawner detail to the game log) is off. Config file is written to <game>/FactoryGame/Configs/HostileScaling.cfg; the same values are editable in-game under Main Menu → Mods → Hostile Scaling (SML's Mod Config UI).

Building the mod

This is C++ source for the SML starter project. You cannot build it standalone — it compiles inside the SatisfactoryModLoader project. One-time environment setup (full guide: https://docs.ficsit.app/satisfactory-modding/latest/Development/BeginnersGuide/dependencies):

1. Install Visual Studio 2022 with "Game development with C++" workload.
2. Install the Unreal Engine — CSS custom engine build (linked from the modding docs; requires linking your GitHub account to Epic).
3. Install Wwise (version specified in the docs) into the engine.
4. Clone the starter project: git clone https://github.com/satisfactorymodding/SatisfactoryModLoader.git

Then:

5. Copy this whole HostileScaling folder into <SatisfactoryModLoader>/Mods/HostileScaling.
6. Right-click FactoryGame.uproject → Generate Visual Studio project files.
7. Build the FactoryGame Editor target (Development Editor / Win64), then open the project in the editor.
8. Open Alpakit (toolbar), find HostileScaling, set your game path (C:\Program Files (x86)\Steam\steamapps\common\Satisfactory) and click Alpakit! to build + install directly into your game's FactoryGame/Mods folder.
9. Build the Shipping client target when you want a distributable .zip for ficsit.app.

Header verification status

All game/SML symbols used by this mod were verified against the actual starter project headers (SatisfactoryModLoader master, July 2026): UFGHealthComponent::TakeDamage signature, mMaxHealth/mCurrentHealth, AFGEnemy, AFGCreatureSpawner::mSpawnData/ mRespawnTimeIndays (int32), FSpawnData fields, GetPurchasedSchematicsOfTypes, UFGSchematic::GetType/GetTechTier, SML config classes (FText display strings), module registration properties, and IFGSaveInterface signatures. Added in v1.1.0: AFGCreatureSpawner::TraceForNearbyBase/mCachedIsNearBase/mSpawnRadius, AFGTimeOfDaySubsystem::GetPassedDays, and AFGWaterVolume::EncompassesPoint.

Runtime-verified: TakeDamage is virtual, so its hook uses SUBSCRIBE_UOBJECT_METHOD (plain SUBSCRIBE_METHOD asserts at startup with "Attempt to hook virtual function override without providing object instance for implementation resolution"). By contrast TraceForNearbyBase is non-virtual, so its re-pin hook correctly uses the plain SUBSCRIBE_METHOD_AFTER. In-game testing confirmed the engine re-runs TraceForNearbyBase roughly every 30 seconds per active spawner, which is why the re-pin hook is required in addition to the periodic sweep.

Config/AccessTransformers.ini grants the subsystem friend access to UFGHealthComponent and AFGCreatureSpawner; invalid entries show up as errors in the build log.

Design notes / known behavior

• Creatures alive at the moment of a tier-up keep their old health scale until they die and respawn. Damage and spawn scaling update within ~10 seconds.
• Spawn-count growth reuses existing spawn locations, so packs get denser rather than wider.
• Respawn Near Factories only writes vanilla-legal spawner state (the same values a natural respawn produces), so it never corrupts a save and is fully reversible — toggle it off and the game re-suppresses spawners near your base within one re-trace cycle. All of its work is server-side, so multiplayer only needs the mod on the host/server.
• Spawners flagged never-respawn in the map data (rare) stay never-respawn. Through v1.0.3 a spawn-scaling bug clamped these to a 0-day respawn, making them respawn daily; v1.1.0 restores their intended behavior (see the changelog).
• Versions up to v1.1.0 scaled every spawner, passive ones included. This version scales hostile spawners only and, on saves made by those versions, walks passive spawners back: creature-less extra pack slots are removed until the pack is back at the size recorded when the spawner was first seen (never below it, and never on a spawner whose recorded size is 0), and the near-base flag is handed back to the game to recompute. With the master Enabled switch off the mod touches nothing, so that residue is left as-is until it is turned back on.
• The mod never edits creature assets, so removing the mod cleanly reverts everything except the (harmless) extra entries it stored in its own savegame data.
• Works alongside MoreEnemySpawns/BloodMoon, but multipliers stack with whatever those mods do — start with low PerTier values if you run them together.

The respawn-keeper technique — resetting a spawner's cleared-kill bookkeeping so vanilla repopulates it naturally — was inspired by Blood Moon by Chris Cavalluzzi as prior art. No code was copied; HostileScaling's implementation is independent.