With Valve’s Halloween event Scream Fortress XVIII still blazing through Team Fortress 2 until November 7, 2026, an indie studio called Breadworks has given TF2 fans one more reason to stay in the game: Mann Versus Zombies, a free total-conversion mod that transforms the 19-year-old class shooter into an eight-player zombie survival experience, is listed on Steam and accepting wishlists now.

Mann Versus Zombies arrives “coming soon” with no confirmed release date, but the trailer and Steam feature list paint a picture of something well beyond a typical fan reskin. The mod supports solo play or online and LAN co-op for up to eight players, ships with a full level editor and Source SDK inclusion, and will carry over cosmetics from a player’s existing TF2 inventory — meaning years of hat-collecting investment transfers directly into the new mod.

Valve’s 2025 SDK Decision Made This Possible

Mann Versus Zombies is not simply a fan project that snuck onto Steam. It is a direct product of Valve’s February 18, 2025 decision to add the full Team Fortress 2 client and server game code to the TF2 Source SDK on Steam. That decision, described at the time as Valve handing “the keys to TF2” to the community, allowed modders to legally build total-conversion standalone games on the TF2 codebase and publish them on Steam for the first time. The non-commercial license terms require all SDK-derived mods to be free — which is precisely why Breadworks can offer Mann Versus Zombies at no cost.

The first major beneficiary of that policy change was Team Fortress 2 Classified (formerly TF2 Classic), which launched on Steam on January 30, 2026 and drew thousands of day-one players. Mann Versus Zombies belongs to the same new class of product: a Steam-listed, free-to-play standalone game that requires TF2 — itself free since 2011 — as its only prerequisite.

Merasmus Tears Open the Veil of Death

The story premise of Mann Versus Zombies plants its tongue firmly in TF2’s cheek while pulling the tone toward something darker. Merasmus — the bumbling sorcerer antagonist who has haunted TF2’s Halloween events since 2012 — returns, but this time with something more consequential than bumper-car curses. He has torn open the veil of death itself, unleashing mutated, rotting, flesh-hungry undead across the familiar battlefields of the TF2 universe.

The mercenaries — Spy, Scout, Heavy, Engineer, and the rest — find themselves no longer fighting each other but fighting together to survive. They appear in zombified form in the teaser trailer, rendered in the same exaggerated slapstick aesthetic that has made the TF2 cast beloved for nearly two decades, now repurposed for dread rather than comedy. The central dramatic question is survival: how many waves can a squad endure before the barricades give out, the perks are depleted, and the horde breaks through?

PC Gamer’s Justin Wagner, reviewing the teaser in May 2026, called it a “Source Filmmaker-powered treat” and noted that if the mod “feels as good to play as it looks, it should be a treat for fans of the venerable shooter looking for a change of pace.”

How Does Mann Versus Zombies Actually Work?

The mechanical template for Mann Versus Zombies draws heavily from Call of Duty’s Zombies mode — a design lineage the developer makes no effort to disguise. Players start with only a sidearm. From there, the loop is: survive a wave, earn in-game currency, buy or upgrade weapons, prepare for the next wave — which arrives harder and more numerous than the last.

The mod’s signature upgrade station is called the Mannifester, a direct nod to CoD Zombies’ Pack-a-Punch machine. Feed a weapon into it with enough resources and it becomes substantially more effective. Between waves, players can also purchase perks — temporary combat bonuses. Breadworks warns, pointedly, that they are “neither cheap nor permanent.”

What separates Mann Versus Zombies from Team Fortress 2’s existing PvE mode, Mann vs. Machine, is structural. Mann vs. Machine features fixed robot-wave sets with a bomb-delivery objective, supports a maximum of six players, and in its advanced tier requires paid Tickets for each attempt. Mann Versus Zombies has no terminal wave — the horde never stops — supports up to eight players at no cost, and positions team coordination around barricade repair rather than bomb interception. As PCGamesN noted in May 2026, MvM can feel like it ends prematurely; Mann Versus Zombies is designed specifically to not have that ceiling.

What Can You Do? What Environment Will You Fight In?

The Steam listing describes multiple distinct maps and environments spanning locales “from the dusty battlements of Teufort to the frozen alpine wilderness,” each offering unique enemy types and challenges. No map list has been confirmed beyond the teaser.

Beyond the core survival loop, the feature set includes:

• Barricade defense — Players must actively repair barricades to slow enemy ingress, adding a tower-defense dimension to resource management.
• Endless scaling — There is no final wave; the mod is explicitly designed as a leaderboard-style endurance test.
• Full Steam Workshop support — Custom maps and skins from the community are built into the roadmap from launch.
• Steam Cloud, level editor, and Source SDK — Breadworks is shipping the developer tools alongside the game, a signal of long-term community investment.
• Family Sharing — Supported, per the Steam listing.

Is This the Right Moment for It?

Mann Versus Zombies has arrived at what may be the most advantageous possible window for TF2 fan projects. Scream Fortress XVIII — TF2’s eighteenth annual Halloween event — launched on October 1, 2026 and runs through November 7, bringing five community-created Halloween maps and a Haunted Hoard Case to the game’s active player base. The timing puts Mann Versus Zombies‘ wishlist campaign directly in front of TF2’s most engaged seasonal audience, at the exact moment players are already primed for the game’s darker, supernatural content.

The mod landscape around TF2 has also never been more active. TF2 Classified‘s successful January 2026 launch demonstrated that the SDK-enabled standalone mod model can attract a real player base. Lambda Fortress and Open Fortress are also listed on Steam under the TF2 mod umbrella. Mann Versus Zombies enters a genuine ecosystem rather than a vacuum.

What Do You Need to Play?

The only barrier to entry is a Steam account and a copy of Team Fortress 2, which has been free-to-play since 2011. Any player who already has TF2 installed is eligible. Minimum system requirements, per the Steam page: Windows 10, a 2.4 GHz processor or better, 4 GB of RAM, a GeForce GTX 400 or ATI Radeon HD 5450 or Intel HD Graphics 4000, DirectX 11, and 4 GB of available storage space. Those are modest bars — approximately equivalent to a machine from 2013.

Breadworks is active across YouTube, X, TikTok, and Instagram at @breadworksteam and maintains a Discord community for updates. The mod’s official website is mannversuszombies.com.

Players can add Mann Versus Zombies to their Steam wishlist page now.

Frequently Asked Questions

How is Mann Versus Zombies different from Mann vs. Machine, TF2’s existing co-op mode?

Mann vs. Machine (MvM), the official TF2 PvE mode launched in 2012, pits up to six players against waves of robots trying to deliver a bomb. It has a fixed wave structure and a defined end point, and advanced “Mann Up” runs require paid Tickets. Mann Versus Zombies has no final wave — the zombie horde scales infinitely — supports up to eight players, costs nothing, and centers on barricade defense and survival endurance rather than bomb interception. The tone also differs: MvM is mechanical and objective-driven; MVZ pushes TF2 into zombie-horror territory.

What do I need to play Mann Versus Zombies, and does it cost anything?

Nothing and nothing. Mann Versus Zombies is free to play. The only requirement is Team Fortress 2, which has been free on Steam since 2011. If you have a Steam account, you can claim TF2 and wishlist MVZ at no cost. Minimum system requirements are modest — a 2.4 GHz processor, 4 GB of RAM, and a graphics card at the level of a GeForce GTX 400 series.

Why can Breadworks publish this on Steam at all — isn’t modifying Valve’s game complicated?

It used to be. Until February 2025, large TF2 mods existed in a legal gray area regarding Steam distribution. Valve’s release of the TF2 Source SDK in February 2025 changed that: it provided full TF2 client and server game code under a non-commercial license, explicitly allowing total-conversion mods to be published on Steam as standalone free-to-play games. Breadworks is operating entirely within that framework. TF2 Classified, which launched in January 2026 under the same policy, was the first major proof of concept.

When does Mann Versus Zombies actually come out?

No release date has been confirmed. The Steam page shows “Coming Soon” with no window announced. Breadworks is active on social media (@breadworksteam) and Discord for updates. Adding the game to your Steam wishlist will trigger a notification when the launch date is announced.