You can invite friends to play the same random dungeon, helping each other and sharing the experience, or competing to see who does best with the same resources.
If you are playing at the same time, you can also see where other players are via an avatar icon.
Note that you do not exist in each other's dungeon, but rather you are exploring the same dungeon independently - either competing to see who makes best use of what they find, or sharing knowledge and loot to make better progress.
Game sharing requires Guild Membership.
First, set Nickname from the guild hall. You will need to tell this to the people you want to play with.
Next, ensure that everyone who is playing is mutual guild friends with the person who will start the game. So for example if Adam will start the game, Betty and Charlie must be Adam's friend and Adam must be both Betty's friend and Charlie's friend. Betty and Charlie need not be friends with each other. The avatars used in-game can be set from the Options -> Game menu; the default on the Web version is the Gravatar associated with your email address (or a random badly-drawn monster if you have not set one); the default on other platforms is an icon for the class you are playing.
Next, one person starts a game from the Multiplayer menu. Shortly afterwards, the other players choose that game from their Multiplayer menu (press Refresh if it is not there yet). They will then get to choose their class as normal before entering into the shared dungeon.
While playing, a network connection is established to show the avatars for all other players and to allow chat and loot trading (only in co-op games). This is optional, you can turn it off by disconnecting in the Networking menu in the left-hand menu. The same menu can be used to reconnect if a player leaves and comes back. Players do not have to play at the same time at all, but it is a fun way to share the experience in "real time" (using a voice-chat program or being in the same room also adds to the fun!).
If you have problems establishing a connection, you may need to try the Advanced Network configuration which is available in the Networking option in the menu while playing. You may need to add firewall exceptions if you are using a router with a firewall. The game does do NAT traversal, but your networking infrastructure may defeat that.
ChattingYou can text-chat with another player by using the same 'Chat' button you would use for talking to your pet. A menu will appear if more than one chat target is available.
TradingIn co-op games, you can trade with another player by moving close to them and using the 'Chat' button. You may then offer each other items. When one player presses "Trade!", the other player's button will pulse indicating that they too should now accept the offer (or not).
You can use the text-chat during trading too. On smaller displays the chat display is toggled with a "Chat" button (covering the trade display).
Note that in Co-op mode, identify scrolls never reveal all items, so there is no reason to pour your entire inventory back and forth before reading every such scroll. Balancing this, discoveries by each player are shared with their co-op partners.
Since players will each do different things, they will experience some differences. The things that are shared are:
- Dungeon layout
- Shops and their contents
- Fountain placement, but not their effects
- Initial creatures found in rooms (but not ones that turn up while you loiter)
- Items found in rooms and from creature (only in competition mode)
Everything else is individual to players.
One thing you may notice is that the spellbooks you discover are biased towards your character's alignment (let's just say it's... well... magic). So a Lawful Good White Witch will more likely find Light spellbooks while a Chaotic Evil Sorceress will find Death spellbooks. The biases are:
|Lawful Good||More light than dark|
|Chaotic Good||More life than death|
|Lawful Evil||More dark than light|
|Chaotic Evil||More death than life|