S.T.A.L.K.E.R. GAMMA (Groks' Automated Modular Modpack for Anomaly) is a hardcore, curated survival experience built on top of S.T.A.L.K.E.R. Anomaly. Designed for stalkers who want a deeper, more immersive journey, GAMMA integrates over 400 hand-picked mods and over 100 specifically developed mods into a single, finely balanced package. No manual modding required, just install, survive, and adapt.

A Zone That Evolves With You

GAMMA adapts S.T.A.L.K.E.R. Anomaly into a longer-form, higher-stakes experience. It encourages cautious exploration, smart inventory management, and tactical engagements across a world that's as deadly as it is dynamic.

With multiple difficulty presets, faction options, and curated progression paths, every run feels different yet always true to the heart of the Zone.

Thanks to its modular nature, every aspect that you want to change in G.A.M.M.A. can be easily tweaked in-game through the Mod Config Menu (MCM) or through ticking and unticking individual mods in the Mod Organizer 2 (MO2) instance it is based on. An entire discord community is ready to help you fine-tune the experience to your liking.

Community-Built. Curated with Care.

This isn't just a modpack, it's the result of thousands of hours of refinement and specific mods development from passionate fans. Designed to be stable, lore-respectful, and challenging, GAMMA is regularly updated and supported via dedicated Discord channels and install tools.

Anomaly was just the beginning. GAMMA is the test of your true stalker instincts.

Top Reasons to play

Built for Survival. Tuned for Immersion

  • True Progression – every piece of gear must be earned. Travel deeper into the Zone to unlock better weapons, armor, and tools, but be prepared for the deadliest threats it has to offer.
  • Overhauled Economy & Looting – no more buy-sell comfort loops. GAMMA removes easy trading and randomized stash rewards, forcing you to scavenge, craft, and survive through intent, not convenience.
  • Body Part Damage & Medical System – injuries now target specific limbs. Managing bleeding, pain, infection, and exposure requires medical planning and a full survival kit; bandages alone won't save you.
  • Artifact Progression – artifacts must be carefully empowered and combined. Instead of instant benefits, they offer meaningful long-term progression.
  • Custom UI & Visuals – enhanced menus, immersive shaders, redesigned HUD elements, and improved performance ensure every moment in the Zone looks and feels intense.
  • High Quality Arsenal – over a hundred weapons have been cherry picked for their high quality textures and animations and all were made compatible with a wide variety of attachments. Every firearm has been finely balanced to ensure a unique feel and playstyle. Thanks to the in-depth repair system, the weapon you maintain and rely on becomes your weapon — not just something you swap out after each looting session.
  • Ballistics That Matter – Every caliber offers multiple ammo types, each with distinct characteristics and uses. Bullets must pierce armor, which gradually degrades with each hit, while mutants demand high-stopping-power rounds to bring them down. Choosing the right tool for the job is essential to surviving the Zone - and doing so without going bankrupt.

How to install?

There are two ways to use the mod.

If you already own the game, install it manually through the full anomaly-mod procedure.

If you don't own the game, buy it on GOG and launch the mod with a single click because the game and mod are packaged together.

⚙️

Manually

1
Purchase the game
2
Get the GAMMA installer separately
3
Install Mod Organizer 2
4
Manually configure the mod load order
5
Troubleshoot any compatibility issues.
6
Hope everything works smoothly together.
Get it on github
FASTEST OPTION
GOG Logo

GOG Way

1
Purchase the game with GAMMA preinstalled using: GAMMAFOREVERCopied! at checkout for a -15% discount on top
2
Enjoy one-click installation for easy setup.
Get it on GOG.com

General FAQ

What does G.A.M.M.A. stand for?

G.A.M.M.A. stands for Grok's Automated Modular Modpack for Anomaly. It's a curated collection of over 400 mods designed to transform S.T.A.L.K.E.R. Anomaly into a hardcore survival experience with enhanced graphics, improved AI, realistic weapon mechanics, and deep crafting systems.

What is the difference between Anomaly and GAMMA?

S.T.A.L.K.E.R. Anomaly is a standalone free mod that combines all three original games into one sandbox experience. G.A.M.M.A. is a comprehensive modpack built on top of Anomaly that adds survival-focused gameplay, scavenging mechanics, realistic weapon maintenance, crafting systems, and visual overhauls. While Anomaly provides the base game, GAMMA transforms it into a challenging hardcore experience.

Do I need to own the original S.T.A.L.K.E.R. games to play GAMMA?

Yes, you need to own at least one S.T.A.L.K.E.R. game (Shadow of Chernobyl, Clear Sky, or Call of Pripyat) to legally play GAMMA. The mod is built on S.T.A.L.K.E.R. Anomaly, which requires the game assets.

Is G.A.M.M.A. good for beginners?

G.A.M.M.A. is designed for players seeking a hardcore survival challenge and has a steep learning curve. If you're new to the S.T.A.L.K.E.R. series, it's recommended to play the original games or vanilla Anomaly first to learn the basic mechanics. However, G.A.M.M.A. is highly customizable through the Mod Configuration Menu (MCM), allowing you to adjust difficulty settings to match your skill level.

Can I customize G.A.M.M.A.'s difficulty?

Yes, G.A.M.M.A. is highly customizable. The name itself means "Gigantic Automated Modular Modpack for Anomaly" - you're meant to tailor the experience. Use the Mod Configuration Menu (MCM) in-game to adjust difficulty settings, damage values, loot spawns, and many other parameters. Mod Organizer 2 allows you to enable or disable specific mods entirely.

Can I add other mods to G.A.M.M.A.?

Adding mods outside the official G.A.M.M.A. modlist is not recommended. The modpack is carefully balanced and tested, and additional mods can cause conflicts, crashes, or break gameplay balance. G.A.M.M.A. already includes over 300 community mods covering most desired features.

Can I play S.T.A.L.K.E.R. G.A.M.M.A. in multiplayer or co-op?

No, G.A.M.M.A. is a single-player experience only. It's built on S.T.A.L.K.E.R. Anomaly, which is designed for solo play. The focus is on creating an immersive, atmospheric survival experience in the Chernobyl Exclusion Zone.

Should I play G.A.M.M.A. or S.T.A.L.K.E.R. 2?

These offer different experiences. S.T.A.L.K.E.R. 2: Heart of Chornobyl is the official sequel with a handcrafted story, modern graphics, and traditional game design. G.A.M.M.A. is a free, community-driven hardcore sandbox focused on survival mechanics, progression, and replayability. Many players enjoy both for different reasons. G.A.M.M.A. emphasizes roleplay and immersion, while S.T.A.L.K.E.R. 2 offers a narrative-driven experience.

What's the difference between G.A.M.M.A. and EFP (Escape from Pripyat)?

Both are major modpacks for Anomaly with different focuses. G.A.M.M.A. emphasizes survival, scavenging, and progression with a desolate atmosphere using muted colors. EFP focuses more on gunplay with access to higher-tier weapons earlier, a more vibrant color palette, and unique ammunition types like explosive and lightning rounds. G.A.M.M.A. has stricter economy and repair systems, while EFP is more action-oriented.

Where can I get help with G.A.M.M.A.?

The official G.A.M.M.A. Discord server has dedicated support channels, troubleshooting guides, and an active community. The GAMMA Wiki on Fandom provides comprehensive documentation on mechanics, items, and locations.

How do I update G.A.M.M.A. to the latest version?

Use the G.A.M.M.A. launcher and click "Update GAMMA data" followed by "Full GAMMA installation." The launcher will verify file integrity and download only updated files.

How long does G.A.M.M.A. installation take?

Standard manual installation typically takes 2-4 hours depending on your internet speed, as the launcher downloads mods directly from ModDB. The GOG one-click installation is significantly faster at 30-60 minutes since the package comes pre-configured.

What are the system requirements for GAMMA?

GAMMA requires a modern PC with at least 16GB RAM, a dedicated graphics card (GTX 1060/RX 580 minimum), and around 100-120GB of free storage space. The enhanced graphics and numerous mods make it more demanding than vanilla S.T.A.L.K.E.R.

Gameplay Mechanics

How does the health system work in G.A.M.M.A.?

G.A.M.M.A. uses a limb-based health system. Your character has overall health plus individual limb conditions. Bandages only stop bleeding and don't restore health. Medkits and stimpaks restore HP to specific limbs. If a limb is broken (shown as a black icon), you'll need a Splint or Surgery Kit to fix it. Painkillers provide temporary health that helps you finish fights but isn't a permanent solution.

How do I repair weapons in G.A.M.M.A.?

Weapons have individual parts that degrade separately. Parts above 60% condition can be cleaned with Gun Oil, Solvents, or Cleaning Sprays. Broken parts (shown in red) must be replaced by disassembling other weapons for spare parts. Barrels cannot be swapped in the field and require a Weapon Repair Kit used at a Workbench. You cannot buy functional weapons from traders; you must scavenge and repair them yourself.

How do I repair armor in G.A.M.M.A.?

Armor repair works similarly to weapons. You'll need appropriate repair kits and materials based on armor tier. Sewing Kits handle fabric repairs while more advanced toolkits are needed for tactical gear. Like weapons, you'll often need to scavenge parts from other armors to maintain your equipment.

How does fast travel work in G.A.M.M.A.?

By default, instant fast travel via the PDA is disabled to encourage exploration and survival gameplay. You can use Tourist Guides found in safe zones like Rostok, Cordon, or the Great Swamps. These NPCs charge money to escort you to other areas. Alternatively, you can right-click on previously discovered locations (green house icons) on your PDA map to travel there.

How do I find artifacts in G.A.M.M.A.?

Artifacts spawn in anomaly clusters throughout the Zone. Equip a detector from your inventory and search anomalous areas. Different detectors have varying detection ranges and capabilities. Selling artifacts to Ecologists is one of the best ways to earn money early in the game. You can also use the Artifacts Melter (sold by Prof. Sakharov and Hermann) to empower, craft, and break down artifacts.

How do I make money in G.A.M.M.A.?

Early game money-making strategies include: completing tasks without getting into fights, selling mutant parts to the Butcher at Garbage, selling artifacts to Ecologists, and disassembling weapons to sell parts below 60% condition to Xenotech in Cordon. Loot enemy patches for patch-collection quests, and read PDAs from defeated stalkers for stash coordinates containing valuable items.

Where do I find Basic Tools in G.A.M.M.A.?

Basic Toolkits are among the rarest items in G.A.M.M.A. There's no guaranteed spawn location. Your best chances are: completing quests (some reward stash locations that may contain tools), thoroughly searching all buildings and containers, and trading with specialized vendors. The Expert Tool Kit can only be found north of the Red Forest, requiring significant Zone exploration.

How does the disguise system work?

Wearing another faction's armor with a faction patch attached allows you to attempt disguises. However, you cannot disguise yourself if anyone is watching you or if a stalker has seen you within the last 24-36 seconds. Equipping weapons or getting too close to stalkers increases your suspicion level. When successfully disguised, you'll receive an on-screen notification.

How do I save my game in G.A.M.M.A.?

By default, quicksaving is only available near lit campfires. Quicksaves elsewhere have a 3-minute cooldown. These restrictions can be modified in the Mod Configuration Menu (MCM) if you prefer more frequent saving options.

S.T.A.L.K.E.R. 2 “Cost of Hope” DLC & G.A.M.M.A.

Does G.A.M.M.A. include the new regions from S.T.A.L.K.E.R. 2's "Cost of Hope" DLC?

Yes, but in their classic forms. S.T.A.L.K.E.R. 2's upcoming Summer 2026 expansion, Cost of Hope, is bringing the Iron Forest and the Chornobyl Nuclear Power Plant (CNPP) to its Unreal Engine 5 sequel. Because G.A.M.M.A. is built on the combined maps of the original classic trilogy, both the CNPP and the Iron Forest are already fully explorable in G.A.M.M.A. right now. If you want to brave these legendary, highly radioactive northern sectors before the DLC drops, G.A.M.M.A. is the ultimate training ground.

Are the storylines of S.T.A.L.K.E.R. 2: Cost of Hope and G.A.M.M.A. connected?

No. G.A.M.M.A. is an unofficial, community-made sandbox experience set shortly after the events of the original trilogy (Shadow of Chernobyl, Clear Sky, Call of Pripyat). It features its own non-canon progression and questlines. The Cost of Hope DLC is the official, canonical middle chapter of the Heart of Chornobyl saga. It focuses on the protagonist Skif and the fragile “D4 Treaty” between the Duty and Freedom factions. Playing G.A.M.M.A. will test your survival skills, but it will not spoil the narrative of the new DLC.

Will G.A.M.M.A. be ported to S.T.A.L.K.E.R. 2's Unreal Engine 5?

Not anytime soon. G.A.M.M.A. utilizes a highly customized, 64-bit version of the classic X-Ray engine (via S.T.A.L.K.E.R. Anomaly). While S.T.A.L.K.E.R. 2 has official mod support and is upgrading its Unreal Engine 5 foundation, building a survival-horror overhaul on the massive scale of G.A.M.M.A. (which contains over 400 interconnected scripts and mods) in a brand-new engine would take the modding community years to develop. For the foreseeable future, G.A.M.M.A. will remain on Anomaly.