The host generates a unique key that other mercenaries can use to join the session or invites them using Steam's friends system. Up to four players can thus play together online. We strongly recommend using a VOIP service to better coordinate with your fellow mercenaries: feel free to check the Gloomhaven official Discord community available here, https://discord.gg/4Nrk6zh .

Once all the players have joined, the host assigns a mercenary to each of her/his teammates.
In the Guildmaster adventure, the players are then free to change mercenary if there are any available left and in both game modes, the player are free to modify the deck and the items of their mercenary.  Depending on the gold ruleset chosen, players can be free to spend the common money of the group. Make sure you communicate with each other to optimize your squad! It is then the host who will choose the mission on the map. Once everything is ready, you will be able to face the dangers that inhabit the region.

If a player is not able to join a session, the rest of the group can go on, one of the remaining players assuming control of more than one mercenary to compensate. She/He can come back later on during the adventure, or a new player can replace the one that is not available any more. Handy indeed when a more experienced friend is thus able to help you during a difficult quest!

The system we designed allows you to automatically download the host's save once the team has joined. Thus, once the file has been saved in "My documents" folder, you can resume a multiplayer game in progress without its initial host by simply loading the save in your game main menu. You will then become the host of the game.