Cepheus Protocol

by
Dev Update

Patch Notes 2025.09.5.3 – public-playtest

How to Opt In

Here’s how to opt into the Cepheus Protocol public playtest on Steam:

  1. Open Steam and go to your Library.

  2. Right-click Cepheus Protocol and select Properties.

  3. In the left panel, click on Betas.

  4. From the dropdown menu, choose public-playtest.

  5. Close the window. Steam will automatically begin downloading the playtest branch.

Once the download is finished, you’ll be running the public playtest version.

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Recap for those late to the party

https://store.steampowered.com/news/app/979640/view/537736957039477252https://store.steampowered.com/news/app/979640/view/537735054151909377

Patch Notes:

  • Gas Towers

    1. Now request Defense Pods as needed

    2. Fixed Oxygen meters not refilling sometimes

    3. Fixed a Delay that would occur after a Gas zone would pop causing Oxygen regen to be delayed as well

  • All Flight models for Helicopters

    1. Flight physics tweaked for realism

    2. Speed, Acceleration improvements

    3. Fixed issues where they would micro move to close move orders

  • Added 2 SOCS to HMB Pandemic

  • Infection Spreading for Inner/Outer zone reduced by 70%.

    1. This now scales up by the day. So they will spend Day 1 mostly staying to themselves unless you try to “bully them”.

    2. Over days their spreading will cascade and increase in pace. Tied to the amount of pods that are in a zone + current population in that zone. It takes much longer to infect larger pools of population now via the revamped systems.

    3. New Zone Card System implemented akin to legacy

    4. Infection Level now displays the current amount of infected presence in your zone.

    5. Infection Cap per Zone

      • Each pod contributes up to 20% Infection Level in the zone it’s placed.

      • Infection stacks per structure, up to a hard cap of 100%.

      Examples:

      • 1 pod → 20% infection

      • 2 pods → 40% infection

      • 3 pods → 60% infection

      • 4 pods → 80% infection

      • 5 pods → 100% infection (zone fully infected)

      The increase doesn’t happen instantly — pods ramp up over time, giving you a chance to intervene before they max out their effect.

      SOC Income Impact

      As zones become infected, your SOC income is reduced proportionally.

      • At 100% infection, a zone is essentially choked out, providing nothing.

      Population Drain

      Infected pods also tick away at the civilian population inside the zone.

      • The higher the infection, the faster people are lost.

      • Left unchecked, pods will snowball, draining both resources and population until the zone collapses.

      A Strategic Layer (Legacy Connection)

      This system returns from Legacy to create a deeper layer of zone management:

      • Hunt pods quickly to preserve your economy and population.

      • Ignore them, and infection will spread until your zones become unsustainable.

  • Juggernauts are now limited by max amount per day. (Will be configurable when we get to implementing the custom game options with a few other options!)

    1. They start with a very low chance of 1 on Day 1

    2. This number increases per day

  • Hardened the attacking logic to resolve an issue where Attack waves couldn’t resolve a base to attack

  • Fixed Activity logs sometimes showing “unknown” when playing online.

  • Fixed Operator falling making units play Stun VFX

  • Fixed Rubble assets not being deregistered from a zone causing the Infected to still think your base was never destroyed in assigning attack tasks from the Infected Faction Manager. Fixed another instance of Attack waves failing.

  • Buff fn_evolys damage from 30 to 38. ggs

  • Buffed flamethrower

  • Applied crash fix speculative for https://discord.com/channels/469412014427602944/1425567404729303100/1425628502039859312

  • Increased Chelsey’s health to 32767,

  • Increased juggs health to 22000.

  • Lowered Juggernaut damage taken by turrest to the jug by 50%

  • Juggernaut Focus logic vastly improved. Some refinement is still needed for transitions from throwing a car to moving. We are still working to finalize his AI and work out the remaining kinks

    https://youtu.be/WNn5wxDbuAEAlso apparently watch out for flying cars…

    https://youtu.be/JpC6c56mXjc

  • Fixed unit groups not working after a changed to toggle landscape using the same keybind

  • Hardened some Async task safeties for seamless travel crashes

  • Fixes for Merlin mesh/LOD.

  • Fixed right-click move orders to properly work onboard the Carrier using the above (also fixes helicopter landing orders on the Carrier)

  • Made LHA6 support Ammo, Medical, Gas & Infection resupply like in legacy https://discord.com/channels/469412014427602944/1328461311599968318/1425399843039215676

  • Fixed player list showing up when in offline mode

  • Korean, Spanish, Russian, Japanese, Brazilian, Chinese, German, French Localizations updated

  • Fixed Infection faction manager shutting off after Chelsey dies

  • Added Operator Crouch recoil reduction https://discord.com/channels/469412014427602944/1328461311599968318/1425369915900170271

  • Toggle landscape added to build mode + key bind widget added to game from legacy

  • Fixed operator Interact appearing in a weird section on the input bindings UI

  • Speculative fix to resolve https://discord.com/channels/469412014427602944/1422444492191039529/1422444492191039529

  • Updated some nav bounds volumes to resolve an issue with helicopter nav on the upper part of HMB Pandemic. Fixes the issue was talked about last CERC HQ on Saturday!

  • Fixed activity log not always updating to the on screen feed , lowered juggernaut max amounts by day

  • Applied speculative crash fixes to https://discord.com/channels/469412014427602944/1424797918950457404/1424797918950457404

  • Applied crash fix for https://discord.com/channels/469412014427602944/1424762384500789448/1424762384500789448

  • Applied crash fix for https://hhttps://discord.com/channels/469412014427602944/1424711489016692818/1424711489016692818

  • Increased min build radius that defense pods are placed from all infected structures

  • Added Juggernaut spawn limiters + fixed a gas tower expansion bug that limited their growth unfairly as days went on

  • Updated Shawnee SK setup. Added Rotor blur setup and Pitch/Roll for better physics sim

  • Speculative fixes for fixing Chesley when she can sometime phases through objects breaking the early Pandemic game mode

  • Fix to resolve juggernauts sometimes spawning in the floor

  • Updated Helicopter ‘throttle usage when under AI control’ to be more aggressive at low speeds – should result in far fewer situations where the helicopters move ‘ultra slow’ to fine-tune their position (such as if they were given a move command that’s very close to their current location, which can happen when fastroping)

  • Fixed Drone not rotating correctly when attacking/chasing targets

  • Fixed Drone being able to leech blood through walls/objects

  • Fixed Drone being able to move while leeching blood

  • Set up new Rotor blur on Osprey, Sparrow, Merlin.

  • Minor VFX fixes

  • Fixed Material Quality settings not going above High.

  • Shawnee speed balance & sparrow overhaul balance/speed

  • Decreased Drone Builder health to 1500 from 4000

  • Speculative safety for Weapon_Base crash

  • Fixed SOCs and some structurers being blocked by bogus volumes

  • Pandemic starting money is 30k now

  • Updated Faction Manager for infected build counter rotation for new CERC Units. Counter waves in the city outside attacks are more effective

What’s Coming Next

Immediate priorities are:

  • Balancing the new Builder Drone and Juggernaut AI

  • Wrapping helicopter polish (directed landings, pads, operator features, desync fixes)

  • Fixing AI issues with enemy prioritization and tactical decisions

  • Frequent bug fixes as we get reports

  • Chelsey’s AI

  • Juggernauts are undergoing testing at the moment

  • Population Meter re-implemented at the bottom-left of the UI for tracking infection strength

Once helicopters and AI stability are locked in, focus will shift to Custom Game Options so players can tune pacing and difficulty. Vehicle driving AI and pathfinding are next in line, but we may hold off depending on the volume and severity of bug reports.

October Goals

We are aiming to flip the rebuild into the default experience by the Halloween Sale, with older versions still available as an opt-in. The exact timing will be based on stability, bug reports, and community feedback — our goal is to get as many people as possible playing on the rebuild once it’s ready.

October priorities include:

  • Implement the AJAX(HUMVEE) as a test bed for vehicle driving. Work with the community to establish a good “core” vehicle driving. After its “done” we start porting over all the wheeled vehicles and follow up with the Abrams and co.

  • Extensive Bug hunts / Performance tweaks

  • A save/load system for Pandemic

  • Bay Area map updates: Treasure Island and Angel Island are under renovation, with rollout expected around Halloween. Stay tuned! We will aim to release this map in segments going into XMAS. Starting in stages

    1. Treasure Island->

    2. Angel & Alcatraz Island ->

    3. San Francisco North

On top of these big-ticket items, there are many smaller details and fine-tuning tasks underway — some not listed here but discussed in recent CERC HQ broadcasts. October will be a mix of large features and constant iteration as we refine the fundamentals.

Community

We had a great nine-player session on Discord right after the latest podcast, with everyone yelling, planning, and strategizing together. These sessions highlight how fun the rebuild already is — but they also expose glaring issues that we’re working hard to fix. We’re confident we’ll keep tackling them throughout October.

https://youtu.be/zKWbgPamjZQ

🎧 Last Time on CERC HQ…

🎙️ Episode Summary: This week’s deep dive delivers a massive progress update on the overhaul of the Pandemic mode, featuring an all-out push to bring full replayability back online. Robert and Michael walk through newly added helicopters—including the Apache, Merlin, and Osprey—complete with functional weapons, revised helipad mechanics, and incoming fixes to air-to-ground UI and landing validation. The team shows off early AI behaviors, pathfinding improvements, and newly implemented features like the activity and build logs to combat co-op chaos and resource confusion.

Combat takes center stage with the first public test of the revamped Juggernaut, now capable of throwing cars and pulling off AOE slams with increasing aggression. A new “Builder” infected enemy joins the battlefield, adding strategic depth as it constructs pods and gas towers. The episode also teases Chelsea’s major rework, aiming to elevate her from a static boss into a dynamic, phase-based threat with self-preservation instincts and map-traversing AI.

Footstep systems are back, voice barks are live for better immersion, and the team is fine-tuning threat evaluation and helicopter pathfinding. Michael breaks down evolving unit balance, while the devs give a brutally honest look at the game’s current difficulty and why this weekend’s builds are not for the faint of heart.

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As the team gears up for adding ground vehicles and save/load systems, they’re clear: bugs are expected in the build they released today, feedback is welcome, and no, this is not final balance—yet. Its all a work in progress as we work to build all the systems back in.

🔥 Highlights:

  • New helicopters fully integrated with weapons, sounds, and visuals

  • Juggernaut overhaul: car throws, ground slams, and rage phases

  • Activity & build logs help curb co-op trolling

  • First glimpse at the infected “Builder” unit

  • Early talk on Chelsea’s rework: roaming, evolving boss AI

  • Helicopter landing logic, visual bugs, and upcoming UI fixes

  • Operator camera work, 2D/3D ability barks, and immersion tweaks

  • Honest dev commentary on crunch, bugs, and upcoming patches

  • Teased features: doctrines, save/load system, custom game rules

🛠️ Patch Preview:
Expect increased helicopter counters, juggernaut fixes, and additional tuning in the next 48 hours. Playtesters: watch for bugs, share feedback, and prepare for a fight—Pandemic just got meaner.

https://youtu.be/j9p7-7UwCAY

🎙️ Next CERC HQ – Livestream Details

🕔 When: Weekly Saturdays – 3 PM EST (New Time!)

📺 Where to Watch:

💬 Topics We’ll Cover:

  • Co-op Progress

  • Total Revamp based on Community Feedback

  • Level Design Updates

🎤 Don’t miss our Live Q&A! We’ll be answering questions from the community during the stream.

📺 Missed a Stream? No Worries!