A Turn-based Strategy game in a futuristic global cold war from the award-winning creators of Out There. Recruit a squad of special agents and run your intel agency to secure the control of the singularity.
All Reviews:
Mostly Positive (188) - 79% of the 188 user reviews for this game are positive.
Release Date:
Apr 18, 2019

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Early Access Game

Get instant access and start playing; get involved with this game as it develops.

Note: This Early Access game is not complete and may or may not change further. If you are not excited to play this game in its current state, then you should wait to see if the game progresses further in development. Learn more

What the developers have to say:

Why Early Access?

“Sigma Theory is a strategy and spy game with many emergent situations. Completing the development with the community will allow us to deepen and balance the gameplay and take the game to places we would not otherwise have planned.”

Approximately how long will this game be in Early Access?

“The Early Access will run for 3 to 6 months.”

How is the full version planned to differ from the Early Access version?

“In addition to the community's suggestions, we're planning new contents and features: 'Story' mode for each playable countries, additional agents and NPCs, new types of exfiltration missions and more exciting stuff that will be unveiled during the Early Access.”

What is the current state of the Early Access version?

“All the features in the 'About This' section are available.”

Will the game be priced differently during and after Early Access?

“The price will be raised at the end of Early Access.”

How are you planning on involving the Community in your development process?

“We are constantly in touch with the community via the Steam forum or the dedicated Discord server, run by the dev team.”
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Includes 2 items: Sigma Theory, Sigma Theory - Soundtrack


Recent updates View all (25)

May 23

Sigma Theory Early Access update 0.16.4

Dear agents, here’s update 0.16.4, where we’ve fixed most of the request from the community plus a wide range of more subtle bugs. We’re very happy to see the list of showstoppers decreasing dramatically, which means we’ll be able to focus more on new content and features in the next updates.

New content
Speaking of new content, we have added a new and mysterious agent that will appear in-game if specific events are triggered. One thing we can tell is that this agent will never let you down and might actually become your best friend.

Quality of life
We've fixed the last (hopefully) UI related glitches and freezes. The game should be hassle free from now on! Also, language settings won't set back to default anymore.

What's up next?
We’ve made good progress on the first ‘Story Mode’. So here’s a bit more info about it!
Each Story Mode will have a unique storyline with missions and dialogues involving new and unique characters with multiple endings. Each ending will unlock a specific character from the Story Mode for recruitment.
Needless to say we can’t wait to share the first ‘Story Mode’ with you! But you'll have to wait a few more weeks before experiencing it!

Full Patchnote
---Version 0.16.4---

Gameplay Changes
  • It is now impossible to set a meeting with a diplomat everyday
  • Mission tooltips now display everything that might influence the chances of success
  • Using a compromising file against a diplomat will prevent you from improving your relation with their country and even decrease the relation
  • Globally increased the negotiation bonus given by compromising files
  • Releasing an enemy spy during a meeting is more efficient
  • Removed Exfiltration Master trait from Agent Espoir
  • Added a new mysterious elite agent

Bug fix
  • Fixed a bug when sending a drone to a conflict zone for an organisation mission
  • Fixed a bug where loading an older save resulted in countries not actually losing the game ever
  • Fixed a bug where language settings were set back to default after a game is over
  • Fixed a bug where language settings weren’t saved
  • Fixed a bug where a dead spouse would still triggered events
  • Fixed a bug where the exfiltration briefing launched by a random event kept showing up after every exfiltration
  • Fixed glitches related to the radial menu that were causing UI freezes
  • Disabled game controllers recognition to avoid them interfering with the camera controls
1 comments Read more

May 10

Sigma Theory Early Access update 0.16.3

Dear agents, here’s update 0.16.3, featuring balancing, bug fixing and community requested changes (and a bit of eye candy too).

In this update, we continued our effort to balance the Diplomacy, and make it less easier to acquire scientists. Our goal is to progressively move the meta toward the exfiltration as the main solution to get scientists as it was originally intended. This will ramp up the overall difficulty of the game and make Strength based agents more useful. We will listen to your feedback and continue to tweak the diplomacy mechanics in future updates if needed.

Each country now has a unique color flavors during exfiltrations to add variety.
We’ve also added new and shiny Soviet buildings that you’ll discover during your missions in Russia.

Quality of life
As widely requested, there is now an option to skip the dialogue animations entirely.
For exotic resolutions, you can now resize the game window to fit your screen accordingly.

Full patchnote
---- Version 0.16.3 ----

  • Offering your gratitude during diplomatic meetings now decreases the trust gauge as originally intended
  • Decreased chances of success when asking for a scientist during diplomatic meetings
  • Fixed various gameplay issues when a country is eliminated: war with those countries is now instantly ended, missions from organisations are cancelled, arrest warrants are removed ...
  • Russia now has some typically Russian buildings in exfiltration missions
  • Different camera filters are now applied in exfiltration mission according to which country it takes place in
  • Added various UI improvements and feedbacks
  • Improved exfiltration loading time
  • Added a visual effect when a branch of the final project is completed, allowing player to see if there are a few missing percents on a slot
  • Added an option to speed up dialogues

  • Fixed bug where the first captured agent could be killed by an event during the same turn, preventing the player from completing the counterespionage tutorial
  • Fixed bug where it was possible to drag the drone on an inactive (and invisible) conflict zone, resulting in unpredictable behaviors
  • Fixed bug where drones weren't given back to the player when they should
  • Authorization by hierarchy to use drones or not is only checked once a turn, preventing various bugs
  • Fixed bug where menus and tooltips weren't properly hidden in some resolutions, leading to a game blocked in the case of menus
  • Fixed occasional freeze when using Mentalis technology for yourself
  • Fixed bug where the game tries to open a conflict zone when all active countries already have an active conflict zone, creating a wide range of problems down the road, like agents not being able to finish their action
3 comments Read more
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“The world needs more games from the creators of Out There.”
Rock Paper Shotgun

“It’s definitely a cool, layered title that has me interested in more.”
Air Entertainment

“If you like board game strategy and micro-management this is completely a game for you.”
That Video Game Blog

About This Game


From the creators of the award-winning sci-fi game Out There...

In the near future, a paradigm-shifting scientific discovery looms over the world, promising radical new technologies. The world’s superpowers realize they could have the power to destroy the global financial system, wipe out entire countries or even gain access to immortality.

However, this discovery — called “The Sigma Theory” — can only be harnessed by a handful of scientists. You are placed at the head of your country’s Sigma division. Your objective is to ensure that it is your nation that reaps the benefits of Sigma Theory before anyone else.

To achieve this you will have powerful resources at your disposal: a cadre of the world’s most elite covert agents, advanced tactical drones and, of course, your own skills in diplomacy and subterfuge.

It’s a cold war out there, one in which mankind must face up to its future.


Turn-based espionage: Use your special agents to dominate the world. Seduction, blackmail, manipulation, industrial espionage… Every low blow is both permitted and encouraged.
Dynamic narrative: Develop and manage your relations with over 100 NPCs: lobbies, armed groups, politicians… Alliance, deception or assassination, you choose.
Field operations: Direct the kidnapping of your targets during gripping pursuits through the world’s greatest cities. Discretion or direct confrontation, your agent’s life is in your hands.

First, recruit a team of four special agents from 50 unique unlockable characters to support your missions. Each comes with their own story, motivations and traits that define their behavior during missions.
Access the investigator, soldier, hacker, seducer and other archetypes to complete your Sigma division and execute your strategy.

When your team is ready, assign them missions around the world to gather scientists, discover compromising documents on local politicians, and more.
Exploit your agents’ abilities to seduce, manipulate and bribe your targets over to your side or have them neutralized.

Other nations will also use their agents to infiltrate your country and seize your scientists. Track, capture and interrogate them to gain information on your enemies, then exchange them for ransom when they are no longer useful.

Order your agents to exfiltrate scientists recruited to your cause during gripping turn-based exfiltration phases through the world’s greatest capitals. Choose the position your drones wisely to support these delicate missions.

In Sigma Theory, diplomacy is the key to achieving your goals. Meet your foreign counterparts and further your objectives using flattery, threats or blackmail. You can also recover your captured agents, advance your research, and much more. Develop your relations with powerful lobbies and armed and influential groups to obtain their favor. But be careful, they may turn on you.

Tech Tree
Sigma Theory is the cause of this cold war. Rally scientists from around the world to your cause to discover new technologies to gain the edge and change the world. Mind control, destabilization of the world economy, robot soldiers, immortality… Will you keep these discoveries for yourself or share them with the world?

Games that inspired us:

XCom, Phantom Doctrine, Plague Inc, Pandemic (board game), Rocket Ranger, Tropico, Armello, Civilization, curious expedition and so much more

System Requirements

Mac OS X
SteamOS + Linux
    • OS: Windows Vista
    • Processor: 1,3 GHz CPU
    • Memory: 1 GB RAM
    • Graphics: NVIDIA GT 440 or AMD Radeon HD 5550 w/ 512 MB
    • Storage: 1 GB available space
    • OS: Microsoft® Windows® 7
    • Processor: Dual-core 2Ghz CPU
    • Memory: 2 GB RAM
    • Graphics: DirectX® 10 compliant graphics card
    • Storage: 1 GB available space
    • OS: Mac OS X 10.7
    • Processor: Dual Core 2Ghz
    • Memory: 2 GB RAM
    • Graphics: Hardware Accelerated Graphics with dedicated memory
    • Storage: 500 MB available space
    • OS: Ubuntu 12.04+
    • Processor: 1,3 GHz CPU
    • Memory: 2 GB RAM
    • Storage: 1 GB available space
    • OS: Ubuntu 12.04+ Desktop only
    • Processor: Dual-core 2Ghz CPU
    • Memory: 4 GB RAM
    • Storage: 2 GB available space

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