Create cross-platform lobbies for listen server games with voice chat, host migration, and Steam integration

Crossplay Lobbies

Lobbies are ideal for listen server games where players gather before starting a match. UCIK lobbies provide:

Voice chat integration
Host migration - lobby persists if host leaves
Presence - friends see your lobby status
Steam shadow lobbies - automatic Steam friends list integration

Creating a Lobby

Use the Create Crossplay Session node with SessionType = Lobby.

Quick Setup

SessionType = Lobby
Visibility = Public
MaxPlayers = 8
bAutoServerTravel = true
bAutoDetectSessionReady = true
MapName = "/Game/Maps/MyGameMap"

This creates your lobby, travels to the map, and automatically marks the session as ready when the server starts listening.

Parameters

Session Name

The internal session name identifier (e.g., "GameSession"). Must be unique per session.

Settings

Travel & Ready Detection:

Parameter	Type	Description
`bAutoServerTravel`	Boolean	Automatically travel to MapName after lobby creation.
`MapName`	String	The map to travel to. Only used if bAutoServerTravel is true.
`bAutoDetectSessionReady`	Boolean	Auto-detect when server starts listening. If false, call SetSessionReady manually.

Lobby Configuration:

Parameter	Type	Description
`SessionType`	Enum	Set to Lobby for listen server games.
`Visibility`	Enum	Public: Anyone can find. Friends Only: Friends only. Private: Invite only.
`MaxPlayers`	Integer	Maximum players (2-64 for lobbies).
`GameMode`	String	Optional game mode URL option.
`Region`	Enum	Region preference (Auto, NA, EU, Asia, etc.).

Lobby-Specific Options:

Parameter	Type	Description
`bEnableVoiceChat`	Boolean	Enable built-in voice chat.
`bEnableHostMigration`	Boolean	Lobby persists and migrates to another member if host leaves.
`bUsePresence`	Boolean	Show lobby status to friends. Only one session can use presence.
`bAllowJoinInProgress`	Boolean	Allow joining after game starts.

Custom Attributes:

Parameter	Type	Description
`CustomAttributes`	Map	Key-value pairs (String, Boolean, Integer, Double) for filtering.

Output Delegates

Delegate	Description
`OnSuccess`	Lobby created successfully. Returns `FUCIK_SessionResult`.
`OnFailure`	Lobby creation failed. Returns error message.
`OnSessionReadyChanged`	Server started/stopped listening.

Usage Modes

Full Auto Mode (Recommended)

bAutoServerTravel = true
bAutoDetectSessionReady = true
MapName = "/Game/Maps/MyGameMap"

UCIK handles everything automatically.

Manual Travel Mode

bAutoServerTravel = false
bAutoDetectSessionReady = true

You call ServerTravel, UCIK detects when ready.

Full Manual Mode

bAutoServerTravel = false
bAutoDetectSessionReady = false

You control everything. Call SetSessionReady(true) when ready.

Voice Chat

When bEnableVoiceChat is enabled, UCIK sets up EOS voice chat for all lobby members. Voice chat works cross-platform - Steam and Epic players can talk to each other.

Host Migration

With bEnableHostMigration enabled:

Host leaves or disconnects
EOS automatically promotes another member to host
Lobby persists, game can continue
OnHostMigration delegate fires (implement in your game mode)

Without host migration, the lobby is destroyed when the host leaves.

Steam Shadow Lobbies

On Steam, UCIK automatically creates a "shadow lobby" linked to your EOS lobby:

EOS Lobby Created - Gets connect string
Steam Lobby Created - Stores EOS connect string as lobby data

This enables:

Steam friends list shows your lobby
Steam overlay invites work
Steam lobby browser can find your game
Players connect via EOS for cross-platform play

Shadow Lobby Data

Key	Value
`EosJoinAddr`	EOS connect string
`IsEosSession`	"true"
`EosSessionId`	EOS lobby ID
`IsListening`	Server ready state

You don't need to manage this - UCIK handles it automatically.

Custom Attributes

Store game-specific data for filtering and display:

Key: "MapName"      → String "Sanctuary"
Key: "GameMode"     → String "TeamDeathmatch"
Key: "MinLevel"     → Integer 10
Key: "RankedMatch"  → Boolean true

Use these when finding lobbies to filter results.

Session Result

The FUCIK_SessionResult returned contains:

Field	Type	Description
`bSuccess`	Boolean	Whether creation succeeded.
`SessionId`	String	EOS Lobby ID.
`PlatformLobbyId`	String	Steam Lobby ID.
`ConnectString`	String	Address for joining.
`bIsListening`	Boolean	Server accepting connections.
`ErrorMessage`	String	Error details if failed.

Platform Support

Platform	EOS Lobby	Shadow Lobby
Windows (Steam)	Yes	Steam Lobby
Windows (Epic)	Yes	-
Mac (Steam)	Yes	Steam Lobby
Linux (Steam)	Yes	Steam Lobby
iOS	Yes	-
Android	Yes	-

FAQs

When should I use Lobby vs Session?

Use Lobby for:

Listen server games (player hosts)
Games needing voice chat
Games needing host migration
Social/party games
Up to 64 players

Use Session for dedicated servers. See Sessions.

Do I need to handle Steam separately?

No. UCIK creates and manages the Steam shadow lobby automatically. Your Blueprint code is platform-agnostic.

What happens if host leaves without host migration?

The lobby is destroyed and all players are disconnected. Enable bEnableHostMigration to prevent this.

Next: Sessions | Finding Sessions | Joining Sessions

Crossplay Lobbies

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