Codex

The Codex is the official web based publication, published by Fantasy Flight Games that highlights rule updates and showcases new content for Twilight Imperium Fourth Edition and eventually the Prophecy of Kings expansion.
The predominant figure behind the codex is Dane Beltrami, the head developer of Twilight Imperium Fourth Edition.
Each Codex contains various sections, including:
*The Omega Initiative: Revised/updated technologies and promissory notes which are intended to replace their original varieties
*Ixthian Artifacts: Entirely new components that players may wish to incorporate into the game if they choose
*Pax Magnifica: Unique scenario/variant for how the game is played
*The Nexus: Community developed content
*Rules Updates: Rules that have been altered/errata'd since release
==Volume I (Ordinian)==
Volume I was released on 31 July 2020. It can be downloaded here.
===Omega Initiative===
====Faction Technologies====
 Magmus Reactor Ω: Your ships can move into supernovas. Each supernova that contains 1 or more of your units gains the production 5 ability as if it were one of your units.Prerequisites: 
 Wormhole Generator Ω: ACTION: Exhaust this card to place or move a Creuss wormhole token into either a system that contains a planet you control or a non-home system that does not contain another player's ship.Prerequisites: Yin Spinner Ω: After you produce units, place up to 2 infantry from your reinforcements on any planet you control or in any space area that contains 1 or more of your ships.Prerequisites: 
Magmus Reactor.png
Wormhole Generator.png
Yin Spinner.png
====Basic Technologies====
 Magen Defense Grid Ω: At the start of ground combat on a planet that contains 1 or more of your structures, you may produce 1 hit and assign it to 1 of your opponents' ground forces.Prerequisites: X-89 Bacterial Weapon Ω: After 1 or more of your units use BOMBARDMENT against a planet, if at least 1 of your opponent's infantry was destroyed, you may destroy all of your opponent's infantry on that planet.Prerequisites: 
Magen Defence Grid.png
X-89 Bacterial Weapon.png
====Promissory Notes====
Stymie Ω: After another player moves ships into a system that contains 1 or more of your units: You may place 1 command token from that player's reinforcements in any non-home system. Then, return this card to the Arborec player.
War Funding Ω: After you and your opponent roll dice during space combat: You may reroll all of your opponent's dice. You may reroll any number of your dice. Then, return this card to the Letnev player.
Cybernetic Enhancements Ω: When you gain command tokens during the status phase: Gain 1 additional command token. Then, return this card to the L1Z1X player.
Acquiescence Ω: When the Winnu player resolves a strategic action: You do not have to spend or place a command token to resolve the secondary ability of that strategy card. Then, return this card to the Winnu player.
Greyfire Mutagen Ω: At the start of a ground combat against 2 or more ground forces that are not controlled by the Yin player: Replace 1 of your opponent's infantry with 1 infantry from your reinforcements. Then, return this card to the Yin player.
Stymie.png
War Funding.png
Cybernetic Enhancements.png
Acquiescence.png
Greyfire Mutagen.png
===Ixthian Artifacts===
====Action Cards====
Name 	#	Play 	Effect
Blitz 	1	At the start of an invasion: 	
Each of your non-fighter ships in the active system that do not have BOMBARDMENT gain BOMBARDMENT 6 until the end of the invasion
Counterstroke 	1	After a player activates a system that contains 1 of your command tokens: 	Return that command token to your tactic pool
Fighter Conscription	1	As an Action: 	
Place 1 fighter from your reinforcements in each system that contains 1 or more of your space docks or units that have capacity; they cannot be placed in systems that contain other players' ships
Forward Supply Base 	1	After another player activates a system that contains your units: 	
Gain 3 trade goods. Then, choose another player to gain 1 trade good
Ghost Squad 	1	After a player commits units to land on a planet you control: 	Move any number of ground forces from any planet you control in the active system to any other planet you control in the active system
Hack Election 	1	After an agenda is revealed: 	During this agenda, voting begins with the player to the right of the speaker and continues counterclockwise
Harness Energy 	1	After you activate an anomaly: 	Replenish your commodities
Impersonation 	1	As an Action: 	Spend 3 influence to draw 1 secret objective
Insider Information 	1	After an agenda is revealed: 	Look at the top card of the agenda deck
Master Plan 	1	After you perform an action: 	You may perform an additional action this turn
Plagiarize 	1	As an Action: 	Spend 5 influence and choose a non-faction technology owned by 1 of your neighbours; gain that technology
Rally 	1	After you activate a system that contains another player's ships: 	
Place 2 command tokens from your reinforcements in your fleet pool
Reflective Shielding	1	When one of your ships uses SUSTAIN DAMAGE during combat: 	Produce 2 hits against your opponent's ships in the active system
Sanction 	1	After an agenda is revealed: 	You cannot vote on this agenda. Predict aloud an outcome of this agenda. If your prediction is correct, each player that voted for that outcome returns 1 command token from their fleet supply to their reinforcements
Scramble Frequency 	1	After another player makes a BOMBARDMENT, SPACE CANNON or ANTI-FIGHTER BARRAGE roll:	
That player re-rolls all of their dice
Solar Flare 	1	After you activate a system: 	During this movement, other players cannot use SPACE CANNON against your ships
War Machine 	4	When 1 or more of your units use PRODUCTION: 	Apply +4 to the total Production value of your units and reduce the combined cost of the produced units by 1
===Pax Magnifica===
Details a new scenario, "Ordinian," featuring 6 preset factions fighting for control of a disabled Argent Flight flagship (which starts in the Nekro Virus' possession). 
===The Nexus===
Features a 6 player galaxy preset, "Right Cat Soup," by Christopher Chick.
===Rules Updates===
*Diplomacy strategy card: The Primary ability has been updated to allow the resolving player to refresh any two of their planets, rather than each planet in the chosen system.
*Hypermetabolism: The printing error has been corrected. The card now reads: During the status phase, gain 3 command tokens instead of 2.
*Gravity Rifts: To avoid a number of unusual mechanical interactions, the timing and exact effect of gravity rifts has been adjusted. Now, units will roll for the gravity rift as they pass through it rather than in the destination system, and units that fail to survive the roll are removed from the board and returned to players’ reinforcements rather than being destroyed—meaning that abilities that trigger when a unit is destroyed are not resolved.
*Retreating with Infantry: Retreating from a combat while transporting ground forces that are on planets in the active system—previously a cumbersome and often confusing process—has been streamlined. Players no longer need to move ground forces from a planet to the space area during the “Announce Retreats” step. Instead, when a ship moves as part of a retreat, it can transport ground forces that are on planets in its system as normal.
*Re-rolls during combat: Abilities that re-roll or modify dice during combat no longer need to be used immediately following a single die roll. Instead, a player can roll dice for all of their units in the combat before deciding which—if any—to re-roll.
Untitled.png|Updated Diplomacy Card 
===The Fractured Void===
The Twilight Imperium Novel by Tim Pratt 'The Fractured Void' was featured.
==Volume II (Affinity)==
Volume II was released on 7 April 2021. It can be accessed here. 
===Omega Initiative===
====Faction Reference Cards====
This section contains reference cards for each of the 24 factions. These reference cards are aimed at giving newer players an understanding of the way each faction plays during drafting.
Each reference card includes summaries of the following information:
*Faction Starting components
*Faction Abilities, Leaders, Tech, Commodity Value, Promissory Notes, Units and Home System
*Faction complexity
An example (Ghosts of Creuss) is shown below 
File:Codex2introsheet.jpg|The Ghosts of Creuss Faction Reference Card 
====Alliance Reference Cards====
This section contains reference cards for each faction's Alliance Promissory Note. This assists greatly in remembering the corresponding ability once it is gained. 
An example (Nomad) is shown below 
File:Codex2introalliance.jpg|The Nomad Alliance Reference Card 
===Ixthian Artifacts===
The Ixthian Artifact section includes 3 new relics, bringing the total up to 13. 
==== Relics ====
 	Effect
Dynamis Core	While this card is in your play area, your commodity value is increased by 2.
ACTION: Purge this card to gain trade goods equal to your printed commodity value +2.
JR-XS455-O 	ACTION: Exhaust this agent and choose a player; that player may spend 3 resources to place a structure on a planet they control. If they do not, they gain 1 trade good.
Nano-Forge 	ACTION: Attach this card to a non-legendary, non-home planet you control; its resource and influence values are increased by 2 and it is a legendary planet.
File:DynamisCore.png 
File:JRXS455-O.png 
File:NanoForge.png
===Pax Magnifica===
====Alliance Game Variant====
This is a brand new optional game mode which allows players to play in teams of two.
See here for more details on this game mode. 
===The Nexus===
Contains interesting galaxy setup maps for 3-8 players that play around the idea of asymmetry.
==Volume III (Vigil)==
Volume III was released on 25 April 2022. It can be downloaded here.
===Omega Initiative===
====Leaders====
The Naalu Collective
*Agent: Z'eu Ω - ACTION: Exhaust this card and choose a player; that player may perform a tactical action in a non-home system without placing a command token; that system still counts as being activated.
*Commander: M'aban Ω - UNLOCK Have ground units in or adjacent to the Mexatol Rex system. - At any time: You may look at your neighbours' hand of promissory notes and the top and bottom card of the agenda deck.
The Xxcha Kingdom
*Hero: Xxekir Grom - Political Data Nexus Ω - When you exhaust planets, combine the values of their resources and influence. Treat the combined value as if it were both resources and influence.
The Yin Brotherhood 
*Agent: Brother Milor Ω - After a player's unit is destroyed: You may exhaust this card to allow that player to place 2 fighters in the destroyed unit's system if it was a ship, or 2 infantry on its planet if it was a ground force.
*Commander: Brother Omar Ω - UNLOCK: Use one of your faction abilities.- This card satisfies a green technology prerequisite. When you research a technology owned by another player, you may return 1 of your infantry to reinforcements to ignore its prerequisites.
*Hero: Dannel of the Tenth - Quantum Dissemination Ω - ACTION: Commit up to 3 infantry from your reinforcements to any non-home planets and resolve invasions on those planets; players cannot use SPACE CANNON against those units. Then, purge this card. 
====Mechs====
The Naalu Collective
Iconoclast Ω	Iconoclast Ω
Other players cannot use ANTI-FIGHTER BARRAGE against your units in this system. 
Sustain Damage	Other players cannot use ANTI-FIGHTER BARRAGE against your units in this system. 
Sustain Damage
2 	6
Cost 	Combat
====Secret Objectives====
Name 	Condition 	Points
Fight With Precision Ω 	Destroy the last of a player's fighters in the active system during the anti-fighter barrage step. 	1
Make an Example of Their World Ω	Destroy the last of a player's ground forces on a planet during the bombardment step. 	1
Turn Their Fleets to Dust Ω 	Destroy the last of a player's non-fighter ships in the active system during the space cannon offense step.	1
===Ixthian Artifacts===
====Frontier Cards====
Codex III Vigil adds 6 new frontier cards, bringing the total to 20. 
Card 	Number in Deck	Effect
Dead World 	1 	Draw 1 relic.
Entropic Field 	1 	Gain 1 command token and 2 trade goods.
Keleres Ship 	2 	Gain 2 command tokens.
Major Entropic Field	1 	Gain 1 command token and 3 trade goods.
Minor Entropic Field	1 	Gain 1 command token and 1 trade good.
====Factions====
An entirely new faction, The Council Keleres (with matching alliance and faction reference cards).