How to Play Inferno Protocol Co-op

Inferno Protocol is built as a social survival game. You can run it solo, and the loop still works, but the store page, the press kit, and every trailer assume a squad. Online co-op supports up to six players. There is no split-screen listing. If someone hosts from the same couch, they still need two PCs or Remote Play — and Remote Play Together is not the same product as the advertised online co-op, a distinction Steam comments already argued during the demo.

This page is the co-op operating manual: how to host, how to talk, how to split jobs, and how to not feed the maze your location. Pair it with getting started for the first hour and maze navigation for marks. Bindings sit in controls.

Hosting and joining

Start from Steam, not from a third-party server browser. Family Sharing is listed. Steam Cloud is listed. A welcoming UI fires when a new player joins a session — that is a courtesy and a warning. If the host is in a QTE or a raid on a camp, wait in the settlement. Demo patches added join / disconnect system messages in text chat. Use them. If someone drops, do not split the remaining five across three biomes.

Launch-week Steam reviews mentioned people getting booted from lobbies and not staying in sessions long. Treat that as Early Access netcode, not as a reason to rage-quit the genre. Wired Ethernet, closed background downloads, and a host who is not also streaming at 4K will save more runs than a better katana. NPC and AI pooling was added specifically to keep large sessions from choking. If the host stutters, the maze stutters for everyone.

Voice is a weapon that cuts both ways

Proximity chat is not Discord with extra steps. The press kit is explicit: your voice can be heard by enemies. That is the Lethal Company-shaped hook Tektonic is leaning on. A demo patch added microphone selection and fixed proximity and walkie-talkie bugs because the feature was central and it was breaking.

Practical rules:

• Default to walkie-talkie or text when you are in a dark interior. Screenshots and trailers show a green handheld radio for a reason.
• Use proximity only for “on me,” “trap left,” and “rat grab.” Do not narrate your life.
• Pick the correct mic in settings. The wrong device is how you transmit a mechanical keyboard to a swamp creature.
• If a player cannot whisper, mute them in OS volume and keep them on text. The maze does not care that they are funny.
• Enemies that hear you are not a bug. If a patrol path suddenly points at your spray wall, assume someone laughed.

Assign one person as comms lead. That person owns the walkie, the call to fall back to the settlement, and the decision to go silent. Everyone else follows. Six open mics is how Junkyard runs end.

Roles that actually help

You do not need MMORPG classes. You need jobs that survive a shift.

• Mark-maker. Spray, chalk, dropped objects. Unique color or symbol per player. This is the person who has read maze navigation.
• Notebook. Draws in real time, marks positions, syncs across the network. Hidden in the Prologue, so this role starts after that chapter.
• Harvester. Melee or quiet kills, then bones, flesh, organs. Feeds crafting.
• Trap lead. Bear traps, teleport traps, fire barrels. Plants on retreat routes, not in the settlement doorway.
• Injector. Carries labeled serums and does not touch unlabeled vials until the squad agrees. See injectors.
• Anchor. Stays near the settlement or a built wall. Crafts from stashes, cooks, watches the gate. Boring. Essential.

Rotate when someone is tired. Do not send all six into a day-occupied interior. Demo notes say some interiors have creatures during the day and empty at night — that is a looting window, not an invitation for a parade.

Combat as a group

Melee stagger is synced. Everyone sees the same flinch. That means one player interrupting a zombie actually saves the player who was about to be hit. Call the stagger. Do not dump shotgun pellets into a teammate’s backstop. Locational reactions exist; if two of you swing at the same skull, you are wasting stamina and making noise.

The trash eater (crocodile-shaped) explodes if you feed it dynamite or grenades. That is a squad tool. The Giant Rat grab is a QTE: one player mashes, the others damage the rat, nobody fires into the victim. Dual-blade users (the claw weapons in official screenshots) need space; shotgun users need a lane. Talk before you enter. More creature behavior is on the enemy ranking and in combat.

Social NPCs are not automatically friends

The maze has a settlement and smaller camps. Some trade. Some will not wait for you to draw first. A six-stack walking into a camp with guns up is a diplomatic incident. Send two, keep four on overwatch, and put the walkie on low. Trade UIs have their own interiors in safe zones; use those rooms, not the street.

False marks are a PvP-adjacent threat even if you never shoot a player. Official copy warns that wrong or deliberately faked marks can lead people into danger. In co-op, agree on a signature. If you see a mark none of you made, treat it as hostile architecture.

After the session

Screenshot the notebook. Dump spare parts into settlement storage. Check patch notes if something desynced — first-time item draws, hand IK, and notebook races were all patched once already. If you intend to climb layers, read the roadmap so you are not expecting Winter tomorrow. Then send the getting started link to the friend who spent the night asking where the map is.