Co-op Guide: How to Host, Join & Play Together

Co-op describes Terraria’s multiplayer modes and how to set up and run shared games so multiple players can play together on the same world. This page explains how to host/join games, control access, and notes common multiplayer formats.

Hosting a multiplayer game (Steam / built-in multiplayer)

From the title screen, choose "Multiplayer" > "Host & Play".
Pick a character to play as or create a new character.
Pick an existing world or create a new world to host.
Choose a Steam multiplayer mode:
- "Friends Only" — any Steam friend can join the session.
- "Invite Only" — only players you invite can join.
Enter a password or leave it blank. If you set a password, only players who know it can join.
After these choices are made, the server starts and you will enter the selected world as the host.

Notes:

The host player’s computer runs the game world; other players connect to that host. Keep this in mind for performance and world persistence—if the host disconnects, other players will be kicked.
Use "Invite Only" and passwords to control who can enter your world.

Joining a multiplayer game

From the title screen, select "Multiplayer" > "Join via Steam" (or the corresponding join option).
Choose a friend’s active session from the list (if they are hosting and set visibility appropriately) or accept an invitation.
Enter the world password if one is required.

Access and session control

Visibility and access are controlled by the host’s Steam mode selection and password.
The host can invite players directly through Steam invites.
For public or larger sessions, use "Friends Only" to allow any friend to join, or use "Invite Only" plus invites to limit attendance.

Multiplayer formats and use-cases

Cooperative play (drop-in co-op): Players work together to explore, build, and defeat bosses in a shared world. Resources, chests, and progress are shared on the world.
Competitive/team play: Terraria can be used for team-based competitions or custom tournaments (for example, Capture The Gem/Flag style community modes), where players or teams compete under agreed rules. Tournament-style games require players to coordinate rules, spawn locations, and victory conditions outside the built-in host settings.
Community-run events: Hosts commonly run events (build contests, boss races, PvP matches) by configuring the world, setting gear/rules, and inviting participants.

Practical tips for smooth co-op

Save backups of your world before large events or experiments; the host’s save is authoritative.
Communicate using voice or chat to coordinate exploration, boss fights, and resource sharing.
Consider server performance: the host’s machine and network connection determine lag and connection stability.
Set expectations for resource/loot rules and PvP (on/off) before starting competitive or tournament matches.

Troubleshooting common issues

Players repeatedly disconnected: check host network stability and firewall/port settings on the host machine.
Cannot find a friend’s game: ensure the host selected an appropriate Steam multiplayer mode, sent invites if needed, and that both players are on compatible game versions.
Host crashes or leaves: progress may be interrupted; have the host rejoin quickly or arrange a dedicated host for long sessions.

This guide covers the built-in Steam multiplayer hosting and common cooperative/competitive usages; additional server software/mods can provide persistent dedicated servers and advanced controls but require separate setup.