Multiplayer was added to Grim Dawn in build 20 and currently uses Steamworks for hosting and joining games across the Internet.
The enemies of humanity are both innumerable and ruthless. It is wise to bring along allies. In Grim Dawn’s multiplayer, you can team up with up to 3 other players to battle against the vile Aetherials and Chthonians. The strength and toughness of monsters scale with the number of players, but so does the amount of loot. It is important to stick together in Multiplayer lest you be overwhelmed by powerful enemies.
To host a Multiplayer session, select Host Multiplayer prior to loading a character into the world. To join a Multiplayer session, select Join Multiplayer instead. You will then be taken to the multiplayer lobby where you will be able to search for active game sessions.
Note that Hardcore characters can only join games hosted by other Hardcore characters, and vice-versa.
In order to host a multiplayer game you need a router that supports either UPnP, or a router that will allow you to manually forward port 27016 for TCP and UDP.
Player vs. Player
Upon hosting a multiplayer session, the host can elect to enable Player vs. Player (PvP) mode. If this setting is enabled, all players who are not in the same party can actively attack and even kill each other. You cannot loot slain players.
Note that death is still permanent for Hardcore characters that engage in PvP, so only duel if you are ok with losing that character.
You can trade items and Iron Bits with players who are in your party. To initiate a trade, right click that player’s status display in the upper left of the screen. You will then see the trade window where you can place items you wish to exchange.
When both players confirm the trade, the items you offered will leave your inventory, and the traded items will be added. Both players must accept the trade before an exchange will take place. If the trade is cancelled, all items and iron bits are returned to player inventories.
Loot in Multiplayer
Grim Dawn features two loot modes: Free-For-All and Instanced Loot. In free-for-all, all items that drop from monsters and chests are available to be looted by all players. Instanced Loot causes loot to drop for each player separately, as if they were in a solo session. The only exception is loot equipped by monsters, which is randomly assigned to players present when the monster is slain.
You can choose between the two loot modes when hosting the game. Instanced Loot is toggled on by default.
Sharing Experience and Iron Bits
Experience gain is shared in multiplayer, as long as you are in the same party. Iron Bits are shared only if you play in Free-For-All mode. For example, if one player picks up a pile of Iron Bits, all players present will receive an equal share of the currency. In Instanced Loot mode, each player collects their own Iron Bits.
If players are not in a party, such as in a PvP session, then experience and Iron Bits are not shared.
Survival mode will be a new mode available after the game’s release, free for all backers (via Kickstarter or through our website’s pre-order). In Survival mode, players will have to give it their all as they fight against increasingly difficult waves of monsters.
More info will be provided on Survival mode as we near its release. See The Crucible for more information.
The GOG and Steam versions of the game are incompatible with each other for network play. The Ashes of Malmouth expansion and core Grim Dawn are incompatible for network play.
To deal with the former, you can install Tunngle, have your players join the Grim Dawn network, and host a LAN game (over the internet!).
Important notice: Tunngle is not available anymore!
To deal with the latter on Steam, you can copy the Grim Dawn folder (call it something like Grim Dawn Malmouth) and then uncheck the expansion tick-box. This will remove the expansion from the Grim Dawn folder and you can play without Malmouth. To revert the change, rename the Grim Dawn folder to Grim Dawn Core and the Grim Dawn Malmouth folder back to Grim Dawn. Check the tick-box to "reinstall" the DLC. Steam will perform a reconciliation, find the required files, and not need to re-download 2G worth of Malmouth.