Imperator: Invictus is a grand modpack and community update to Imperator: Rome, also found on the Steam workshop here and the PDX store here.
(Achievement compatible on 2.0.4, works on Ironman and MacOS now)

To install, extract the files in your Documents\Paradox Interactive\Imperator\mod folder directly.
To continue old saves, you can download the old files from the Nexusmods archives.
We also have a wiki: https://imperator.paradoxwikis.com/Imperator_Invictus

Major mod features: V1.7.1 - Vesuvius

• A vastly improved AI based upon Glavius' work
• Tons of new Mission trees (list is below)
• Map expansions in North-Africa, East-Africa, European Steppes, Burma and more
• Reworked map setup in: Arabia, Iberia, the Balkans, Germania , Sardinia, Ukraine, the Steppes and East-Africa with several new nation tags
• Added many new impassable mountain ranges in North-Africa, Iberia and India
• Added new navigable rivers, Lake Tritonis/Bazensis (Tunisia) and the Marib Dam (Yemen) physically to the map
• Added several wonders (with 3d models) including the Second Temple, the Marib Dam, Athenian Acropolis and the Ziggurat of Ur
• Dynamic food production and consumption system with varied Seasons and increased importance
• A total rebalance/rework of all Buildings
• A total rebalance of Military Units (including cultural names)
• A total rebalance of Wonders
• A total rebalance of Laws
• Added the Spearmen unit type
• Added 8 new tradegoods: Cedar, Sugar, Myrrh, Cinnabar, Lapis, Jade, Fruit and Silphium
• Historical Galatian invasion decisions and events (mission tree is under development)
• Historical but dynamic Mauryan collapse
• Historical but dynamic Parthian invasion
• Optional Gamerules for the Reworked Diadochi CB, Dynastic Names for the Diadochi, the seasonal food and more
• A dynamic character Background art system
• 200+ new generic events
• Dozens of new Schemes, Ambitions and Character interactions
• Spartan Diarchy reflecting Sparta’s historical government form of 2 Kings.
• Tons of new custom art for Deities, Cities, Wonders and more
• Flavour events for Kemetics/Germanics/Illyrians and more (100+)
• Larger revolts for when other provinces are close to rebelling
• Added tons of Deities to forgotten religions (150+) and plenty of new religions
• Added tons of Treasures spread around the World
• Dynamic tech spread for Tribes
• Decisions to build up rare tradegoods
• 7 new disasters: floods, landslides, droughts, (sand)storms, avalanches and locusts
• Buffed early-game tribes for increased survivability and military importance
• Many new Military traditions and reworked military tradition requirements
• New heritages spread around the world (100+)
• Improved Wonder Building
• Tons of balance changes to make the game better, including important character stats, bloodline traits and general modifiers
• A lot of new cultural inventions (60+)
• More historical AI behaviour, including Epirote invasion of Italy
• Reimplemented the old Slave Revolt mechanic
• 4 languages to play in: English, German, French and Spanish
• And many other various pieces of content/flavour
  

Mission trees:

• 6 new Mission trees for Cyrenaica
• 4 new Mission trees for Thebes
• 3 new Mission trees for Macedon
• 2 new mission trees for Aksumites, Etruria Gymnaesians, Heraclea Pontica, Kios, Rhodes, Maurya, Samnium, Sardinians, Suebians, Tasm, Ingvaeonics into Saxonia, Istvaeonics into Francia and the Tamil Kings (Chola, Chera and Pandya)
• 1 new large Mission tree for Albania, Atropatene, Bharatvarsha, Bithynia, Cappadocia, Judea, Kalinga, Kush, Lanka, Mauretania/Massaesylia, Nabatea, Nabhapakti, Paurava, Persis, Samaria, Scythia, Sogdia, Tartessians, Tibet, Treveria, Vasconia, Veneto, Yamnat and Zhangzhung
• 1 new regional mission tree for Aremoricans, Argos, Bastarnae/Sciria, Bohemia, Caledonia, Carthage, Cisalpine Gaul, Colchis, Cretans, Dumnonia, Eburonia, Fezzani, Fugandulu, Getae, Gordyene, Gothonics, Hibernians, Iberia, Icenia, Korkyra, Messapia, Odrysia, Qataba, Rhaetia Roman invasions of Britain/Rhaetia/Illyria, Saba, Tylos, Umbria, Vandals and Yaudheya
• Generic mission tree for Bharat
• 7 Mission trees for Bactria into Indo-greek Kingdom
  

Invictus is Latin for unconquered, undefeated; our English word 'invincible' takes its root here.

Given the unfortunate news concerning the game status, we thought it best to combat an attitude of defeat with a fighting spirit.

This mod is our effort to prevent this great game from going gently into that dark night. Thus we are embarking upon a grand effort by the modding community (based around the Imperator mod COOP) to develop community-driven DLC and keep the game alive.

It is not our intent to completely overhaul the game mechanics, as we want people to be able to play the mod and understand everything while having only played Vanilla.

Links:
Discord: https://discord.gg/5K9fd3qSjx. (Active community, receives weekly teasers and announcements)
Official twitter: https://twitter.com/InvictusMod
Follow our dev diaries on the PDX forums: https://forum.paradoxplaza.com/forum/threads/mod-imperator-invictus.1473328/

In terms of suggestions, our goal is that anyone familiar with only vanilla Imperator should be able to pick up the mod and play without trouble, all features must be either historical or reasonably plausible and fun.

As this is a community project, we will listen to and work in the interest of the Imperator: Rome community and we look forward to hearing from you!


If you find any bugs, you should contact us in the Bugs channel on our Discord, or place a message in the Bugs steam discussion, please do not use comments for Bug reports.

Credits to the Invictus team and everyone who helped us in no particular order.
Devs:
Snowlet, Jphiloponus, Mike Bittersteel, Dementive, Erik Erik, Hannibal_theCannibal, Izn, OmegaCorps, Palando, Parcipal, Paulus, Sealionforever, Thymos, Torugu, Tudhaliya, Aerozona, Diskianterezh, gmb360, Idonea, IhateTrains, Olivenkranz, Shocky27, Stallone, Typhion, Zorgoball, rickinator9, Acult, TheMadRegent, derekmark, MikeW, Two-Coops
Artists:
Aquizar, CrazyZombie, Fildez, Nerdman3000, RetconCrisis, Kailas, crownsteler
Translators
Apollon, Frank, Juanen, Julianus, Lemon, Machiavello, Pilar, Spikos, Vityviktor
Contributors:
Agamidae, Arkerios, Ben4Peters, DaFoogle, Diego I de Persia, Dustin, Hexon, Kalen, MattTheLegoman, Nebular, Pardo, Presidentstorm, .ianfleming, Shinymewtwo99
Prometheus, Licarious, AtomicFission, Sobisonator, IsaacCat, NPK
Testers:
Augustus_Caesar, bla, Brasidas, DDJR, FBI Agent, Jake_P, Jandoski, Lil_squindie, llamafanatic, Memer Nener, Pydras, Sav, Somebody, Trewajg, Tuko Tuko, Eel, Mateusz, Salt
Scholars:
Chehrazad, Derek, Felix Amiculus, Herodotus, INKRSN, Manny, QuietRustler, Sethos, Trarco

Special thanks to:
CK3 Apotheosis - For allowing us to use their Coat of Arms
Conqueror/BlackExcellence/Julianos - For allowing the use of their models.
Agamidae - for helping the whole modding community as COOP lead.
Aquizar - for allowing us to use his high-quality profesional artwork.
MattTheLegoman - for doing amazing work on the Terrain.
Terrapass - for sharing how to make font appear above trees.
Londoninium - for fixing COA textured emblems.
Verneylive - for allowing the use of his background art.