An Extraterrestrial Encounter Expansion for DayZ

Website • Information • Key Features • Content • Server Setup • Configuration • Classnames • Changelog • Credits • License

Information

Alien Invasion brings a pulpy science-fiction encounter to DayZ. UFOs come down like helicopter crashes, wrapped in a toxic cloud, with alien technology in the wreckage and hostile little green men waiting for whoever comes to look. Survivors who make it through can recover experimental plasma weaponry and alien materials—and, naturally, protect themselves with a tin foil hat that actually works.

The mod includes custom models, textures, sounds, particles, localized item names, and Enforce Script behavior. It is designed for both the server and every connecting client.

Key Features

• A custom UFO crash site with green light, fire, a smoke column, crackling electrical sparks, mist, wreck particles, distant crash audio, and an 18 m toxic gas zone (NBC gear protects).
• Crash salvage: a 35% chance of a Montauk Rifle with a cartridge, plus up to two spare cartridges.
• Hostile Little Green Men with their own voices and footsteps, and green blood. Infected melee up close, a visible psychic zap from 4–80 m in line of sight, and a green burst and scream when they die.
• Aliens appear when a player comes within 300 m, so unvisited crash sites cost the server nothing.
• Montauk Rifle, a semi-automatic plasma weapon whose bolts deal double damage to aliens (other firearms deal 75%). Its cartridges come in green, blue, lime and violet, and each colour has its own muzzle effect, bolt and light.
• Montauk Cartridge, a 15-round plasma magazine that can't be unloaded — recharge it with a 9V battery.
• Tin Foil Hat: aliens can't track the wearer beyond 3 m and can't zap them.
• Area 51 Steak and Roswell Hide from skinning aliens. Cooked steak gives 90 s of green night vision; bad meat gives food poisoning.
• Roswell Hide crafting: tan the hide into green Roswell Leather, then sew a Roswell Leather Backpack, or make a Roswell Hide Courier Bag and Roswell Hide Backpack.
• Specimen Tank prop for admins and map makers: a sleeping alien floating in glowing green fluid, with rising bubbles, drifting motes, a green light and a low hum (geb_AlienTank).
• Every number is tunable in $profile:Gebs/alieninvasion.json, and the server generates its own economy files.
• Complete string-table support for English, Czech, German, Russian, Polish, Hungarian, Italian, Spanish, French, Traditional and Simplified Chinese, Japanese, and Portuguese.

The Encounter

When a geb_Aliencrash object is created through DayZ's Central Economy (or with an admin tool on a dedicated server), it:

1. Plays the mod's distant UFO-crash sound (Central Economy spawns only).
2. Displays the wreck's custom fire, smoke column, electrical sparks, mist, glow, and particle effects for clients.
3. Surrounds itself with a toxic gas cloud and drops its salvage nearby.
4. Waits for a player to come within 300 m, then spawns 10–15 Little Green Men 5–25 m around the wreck.
5. When the event ends, removes its gas cloud and any surviving aliens along with the wreck.

The wreck is the encounter anchor; you never configure alien spawns separately.

Content

Little Green Man

The alien is based on DayZ's infected behavior and uses its own model, voice, and footsteps. Up close it fights like an infected; when it's chasing you in the open it zaps you from range. It can be skinned with any knife or cutting tool, producing two Area 51 Steaks, a Roswell Hide, and vanilla gutting materials.

Montauk Rifle

The plasma rifle is a semi-automatic firearm built on the Ruger 10/22 weapon base (config and script both). It uses the dedicated Montauk Cartridge and fires green plasma bolts that hit aliens twice as hard as ordinary bullets.

Montauk Cartridge

A sealed 15-round plasma magazine. It can't be unloaded; combine it with a 9V battery to recharge it. A full battery fills a full cartridge.

Alien Materials

• Area 51 Steak inherits DayZ's meat preparation and cooking states. Eaten cooked (baked, boiled, or dried) it gives 90 seconds of green night vision; raw, burnt, or rotten it gives food poisoning.
• Roswell Hide is the alien's harvestable pelt. It is green at every step of vanilla's leather chain:
  • Hide + garden lime (by hand or in a barrel) → Roswell Leather, up to 12 per hide.
  • 2 Roswell Leather + leather sewing kit → Roswell Leather Backpack (6×7 cargo).
  • Hide + rope → Roswell Hide Courier Bag (5×6); + 3 wooden sticks → Roswell Hide Backpack (7×5).
  • Each bag breaks back down with a knife or blade, like vanilla's.

Tin Foil Hat

A lightweight hat that really does keep the aliens out of your head: they can't track an intact foil hat's wearer beyond 3 m, so they can't zap them either.

Requirements

• DayZ
• The mod must be loaded on both the server and client.
• No third-party mod is declared as a runtime dependency.
• Subscribe on the Steam Workshop to receive the published mod and updates.

Server Setup

1. Install the mod folder and key on the server, and add it to the server and client launch parameters.
2. Start the server once. The mod writes alieninvasion.json and six economy files into $profile:Gebs/ (next to Gebsfish's, if you run it):

   <profile>/Gebs/
   |-- alieninvasion.json
   `-- mpmissions/
       |-- alieninvasion-types.xml
       |-- alieninvasion-spawnabletypes.xml
       |-- alieninvasion-events.xml
       |-- alieninvasion-cfgeconomycore.xml
       |-- alieninvasion-cfgeventspawns.xml
       `-- alieninvasion-mapgroupproto.xml
   

3. Copy the types, spawnable types, and events files into mpmissions/<mission>/alieninvasion/ and paste the <ce folder="alieninvasion"> block into the mission's cfgeconomycore.xml.
4. Merge the StaticAlienCrash positions into cfgeventspawns.xml (79 hand-picked sites on Chernarus; other maps reuse their heli-crash positions) and the wreck's loot group into mapgroupproto.xml.
5. Restart. Don't add the old InfectedAlien secondary event — each wreck spawns its own aliens.

The generated files are only rewritten when the mod version changes, and the mod never edits your mission folder itself. Step-by-step instructions with copy buttons are on the website; a plain-text version is in docs/server-guide.txt.

Configuration

$profile:Gebs/alieninvasion.json holds every tunable, all server-side:

Setting	Default	What it does
CrashAliensMin / CrashAliensMax	10 / 15	Aliens per wreck
CrashAliensSpawnDistance	300	Metres a player must come within before aliens appear (0 = immediately)
CrashRifleChance	0.35	Chance of a Montauk Rifle in the wreckage
CrashSpareCartridgesMax	2	Spare cartridges per wreck
CrashGasZone	true	Toxic cloud around each wreck
PsychicZapEnabled	true	Aliens zap their target at range
PsychicZapMinRange / PsychicZapRange	4 / 80	Zap distance band in metres (needs line of sight)
PsychicZapCooldown	60	Seconds between zaps per alien
PlasmaDamageVsAliens	2.0	Plasma damage multiplier against aliens
OtherFirearmDamageVsAliens	0.75	Other firearms' damage multiplier against aliens
FoilHatDetectRange	3	Aliens can't target a foil hat's wearer beyond this
AlienVisionSeconds	90	Night vision from cooked alien meat
BadMeatPoison	100	Food-poisoning agents per bite of bad meat

A file that fails to parse is never overwritten; the server logs the error and runs on defaults.

Classnames

Classname	Type	Description
geb_Aliencrash	Encounter object	UFO wreck with effects, audio, gas, salvage, and alien spawning
StaticObj_geb_Aliencrash	Static object	Visual UFO wreck without the scripted encounter behavior
geb_AlienRadiationArea	Effect area	The wreck's toxic cloud (created and removed by the wreck)
geb_GreenAlien	Creature	Hostile Little Green Man
geb_AlienTank	Prop	Specimen Tank with a sleeping alien; place it with an admin tool or editor
geb_GreenAlienMeat	Food	Area 51 Steak harvested from an alien
geb_GreenAlienSkin	Material	Roswell Hide harvested from an alien
geb_GreenAlienLeather	Material	Roswell Leather, tanned from the hide
geb_GreenAlienLeatherSack	Backpack	Roswell Leather Backpack
geb_GreenAlienCourierBag	Backpack	Roswell Hide Courier Bag
geb_GreenAlienImprovisedBag	Backpack	Roswell Hide Backpack
geb_PlasmaRifle	Weapon	Semi-automatic Montauk Rifle
geb_PlasmaCartridge	Magazine	15-round Montauk Cartridge (rechargeable), green plasma
geb_PlasmaCartridge_Arc	Magazine	Montauk Cartridge (Blue): blue arc plasma
geb_PlasmaCartridge_Lance	Magazine	Montauk Cartridge (Lime): lime lance plasma
geb_PlasmaCartridge_Void	Magazine	Montauk Cartridge (Violet): violet void plasma
geb_FoilHat	Clothing	Tin Foil Hat

Project Structure

alieninvasion/
|-- config.cpp          # Mod registration and script-module definitions
|-- data/               # Entity configs, models, textures, and sounds
|-- docs/               # GitHub Pages site and plain-text server guide
|-- graphics/particles/ # Plasma, UFO, green blood and specimen tank particles
|-- languagecore/       # Localized display names and descriptions
`-- scripts/
    |-- 3_game/         # Version, server config, file generator, alien-vision tint
    |-- 4_world/        # Wreck, aliens, specimen tank, gas zone, rifle, items, recipes, player hooks
    `-- 5_mission/      # Server startup: loads the config, writes the Gebs files

Credits

• Geb — creator and author
• The DayZ Modding Community

Contributions and bug reports are welcome through this repository's issues and pull requests.

License

Alien Invasion is distributed under the GNU General Public License v3.0. You may use, study, modify, and redistribute the source under the terms of that license.

DayZ and Bohemia Interactive are trademarks or registered trademarks of Bohemia Interactive. This community project is not affiliated with or endorsed by Bohemia Interactive.