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v3.3 Halloween Update Released

Zombie Panic! Source · Community Announcements · October 30, 2025

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Hello everyone! We're very excited to introduce the long-awaited v3.3 patch and to announce our plans to migrate Zombie Panic! Source to the latest 'TF2 SDK' update-branch!

What does this mean?

Back in February, Valve released a massive update to the Source SDK which adds Team Fortress 2's client and server game code, making it possible for modders to change or rewrite TF2 however they like. This update brought a lot of cool new features, changes, and improvements to all of Valve's multiplayer Source engine titles, such as 64-bit support, Steam Networking (Peer-to-Peer) and many more.

Our programmers are currently in the process of bringing all of those features into ZPS and they will arrive in future updates when they are ready. We'll have a detailed dev blog explaining each one of those new features, what we've been working on, and new upcoming content in the near future!

What's new?

Today's update includes the first phase of our TF2 SDK migration plan, focused on specific changes and improvements to the game that don't change anything within the game engine for a faster release and to fix any technical bugs from the initial port. We'll highlight and discuss the most important ones included in this patch, followed by a full changelog below!

Networking Optimizations

The first changes from the TF2 SDK implemented in this patch are improvements to networking precision and lots of client-side prediction fixes, resulting in less hit registration errors and better game-feel. Players with high ping latency might notice some improvements in this aspect. Please let us know in our forums of any issues you find when playing!

Steam Workshop Improvements

We've made significant changes to our Workshop mounting to support VPKs that should result in better game performance and reduced loading times. Players with lots of subscribed items will notice this change clearly when launching their game. We highly recommend to all Workshop authors to pack your items into a VPK file for this change to take action!

We also want to mention that the "custom" folder will no longer be used. From now on, we require you to move any custom content you have there to the "addons" folder instead, since it's not very efficient to have two mount points that do the same job. Packing your own custom content into a VPK also helps!

More detailed info about this in the readme.txt file in your 'addons' folder! Or check guide below!

[dynamiclink href="https://steamcommunity.com/sharedfiles/filedetails/?id=3597684368"]

Game Settings Changes

There is a 'new' setting in "Video -> Advanced" called "Material queue mode" (aka mat_queue_mode) for you to change with an extra description of what it does. This option was always forced to "1" in the past due to reasons that aren't relevant anymore, and we want to let you know that you can now manually toggle this option!

We unfortunately had to remove both "Multicore rendering" and "Windows Aero" options from the advanced settings; the first was causing users to get stuck in a listen server, and the second was not really applying the change anyway. You can still use the host_thread_mode CVAR in the console for multicore rendering, and you can add the command-line argument "-nod3d9ex" in your game's launch options to disable Windows Aero extensions. Keep in mind we do not recommend messing with these options as they might threaten game stability and thus your gameplay experience.

Gameplay Tweaks

According to player feedback and past community surveys, players have been asking for changes to the player movement speeds and stamina/fatigue regen. We wish to let you know that we've made some improvements in this regard that should make the Survivors less exhausting with walk/duck mode being slightly faster and recovering stamina much better than before.

We also took this opportunity to increase the head damage multiplier on Pistols, Revolver and Rifles to feel more rewarding as we agreed it was really underwhelming (base dmg had to be tweaked as a trade).

Patch Notes

Addons system & Steam Workshop

Achievements

Angelscript

Audio

Client

Debugging bots

Entities

Game rules

General

Localization

Maps

Player

UI

Weapons

Developers Note/TL;DR

The 'TF2 SDK' release is a great opportunity to bring ZPS to the latest (free for use) Source engine branch that includes lots of new features (64 bits, Steam Networking etc...) that the community could benefit. However, most of them requires heavy changes to its engine, resulting extensive work and dedication from our programmers. Therefore, we decided to release this patch with everything available from the TF2 SDK update that doesn't change anything within game's engine, including lots of quality of life fixes, game balance changes (per community request) and lots of miscellaneous.

We'll being the pre-production of ZPS v4.0 in the near future to test the waters of those new features, see if they can be implemented or not, take this chance to rework technical areas of our game and then have a playable build for testing. Everything is a working in progress and subjected to change. We'll publish a devblog later on discussing all the possibilities of the port, our future plans for the franchise and any upcoming content (official and from community contributors).

Until then, please enjoy this Halloween update and let us know what you think by discussing below, make sure to report any bugs or issues you find in our forums! 🎃

The Zombie Panic! Team

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