Multiplayer Cross-platform Functionality

Requirements and cross-play social graph options

8 min read

Requirements

All titles coming to the Epic Games Store that have online multiplayer must support cross-platform multiplayer with all other PC storefronts. This policy ensures that players who purchase a multiplayer game on the Epic Games Store can easily connect with other players in-game, regardless of where the game was purchased. Cross-play with other non-PC platforms, like consoles, is optional but encouraged.

Matchmaking

For products that support matchmaking, players must be able to match-make across storefront boundaries by default. Specifically:

  • All Steam and Epic Games Store games should be listed together.

  • An Epic Games Store player can join a Steam game or an Epic Games Store game listed in the multiplayer menu.

  • A Steam player can join a Steam or an Epic Games Store game listed in the multiplayer menu.

Friends-Based Multiplayer

For products that support friends-based multiplayer, players must be able to view and interact with friends across platform boundaries. Examples of friends-based multiplayer functionality include but are not limited to joining sessions via presence, asynchronous friends-based play, and other friends-based interactions.

Invites

For products that support invites, invites must be supported across storefront boundaries. These invites should work bi-directionally, in a similar manner to how they work on their native platform, so:

  • An Epic Games Store player has a way to send an invitation to a friend playing on Steam.

  • A Steam player has a way to send an invitation to a friend playing on the Epic Games Store.

If your game supports direct invites on the same platform, code-based invites across storefronts are not sufficient to meet the cross-platform multiplayer requirement.

Learn more about Cross-play Social Graph Options to support invitation systems.

Epic will review any product with online multiplayer to ensure adherence to these standards. If your product uses online multiplayer functionality, you must submit the build for review a minimum of 4 weeks before your intended launch date. If you have any questions about the requirements for online multiplayer games, you can contact the Epic Games Store team via a case.

Epic Online Services for Cross-Platform Multiplayer Support

While developers may use Epic Online Services (EOS) to support these requirements, EOS is not required; developers may choose any third-party solution-providers or in-house solutions to ensure the title meets the stated requirements. Learn more about Epic Online Services.

If you have any questions about setup for your multiplayer game, please contact your Business Development Manager or Technical Account Manager.

Cross-play Social Graph Options

Invitation systems largely depend on the player’s social graph to provide addressable users as targets for invitation. The Epic Games Store recommends the following options for cross-play social graphs:

  • Epic Social Graph – Uses Epic Account Services-based social graph as the primary social graph across all PC storefronts.

  • Publisher Social Graph – Uses a title-, developer-, or publisher-based social graph as the primary social graph across all PC storefronts.

  • Bifurcated Social Graphs – Uses the social graph of the PC storefront where the client was purchased as the primary social graph (the “Home” social graph). Optionally, allows for linking to another storefront’s social graph (the “Away” social graph) as a way to satisfy the invitation requirement. Necessitates additional UX for showing the “Away“ social graph, either collated in-game friends lists, or additional social graph overlays.

Epic Social Graph

Epic Account Services are designed to work across platforms to provide a consistent developer and user experience. Learn more about Epic Online Services and Epic Account Services.

Pros
  • Large social graph – the Epic Account Services have more than 350 million accounts and over 2.2 billion friend connections

  • Single identity on all platforms – makes development and support easier across platforms for developers. Users maintain a single online identity and friends list across titles and platforms.

  • No blockers – Epic Account Services are supported on all major platforms, storefronts, engines, etc.

Cons

A change for existing users – for titles that have previously ​shipped using other social graphs as their primary, updating to Epic Account Services as the primary social graph may be disruptive. In these cases, we recommend using bifurcated social graphs.

Additional Options
  • Integrated friends – optionally link with other social graphs, including other publisher- or platform-based social graphs where applicable, to display additional friends lists in-game

  • Suggested friends – optionally link to another account to suggest Epic friends to another social graph

  • Reciprocal friends – optionally link to another account to have Epic Account Services receive friend suggestions from another social graph

Typical Tech Stack

Typically, a game client leveraging Epic Account Services for the primary social graph would also use EOS services. This is not a requirement.

StorefrontEpic Games StoreSteamPublisher Store
ServicesEpic Online ServicesEpic Online ServicesNot applicable
SocialEpic Account ServicesEpic Account ServicesNot applicable
StoreEpic Games StoreSteamNot applicable

Publisher Social Graph

Some developers or publishers have the capability of supporting their own social graph. These solutions are welcome on the Epic Games Store.

Pros
  • Storefront equality – by default, when using a publisher social graph as the primary social graph, PC storefronts are treated equally

  • Single identity on all platforms – makes development and support easier across platforms for developers. Users maintain a single online identity, no matter where they play

Cons
  • Expensive – not all developers/publishers have the capability to implement, maintain, and constantly draw users to their own social graphs

  • Small(er) social graphs – publisher-focused social graphs tend to have fewer users and social connections between those users, than social graphs spanning multiple publishers

  • Account linking requirements – users may get confused if they purchase a game with one identity, but then play that game with a separate identity and have a friends list that does not match the platform/storefront’s friends list

Additional Options
  • Integrated friends – optionally link with other social graphs, including other publisher or platform social graphs where and when available, to display additional friends lists in-game

  • Suggested friends – optionally link to Epic Account Services to suggest Epic friends to the publisher social graph

  • Reciprocal friends – optionally have Epic Account Services receive friend suggestions from the publisher social graph

Typical Tech Stack

Typically, a game client leveraging their publisher account for the primary social graph across storefronts also uses their own game services. They may also have their own storefront. This is not required.

StorefrontEpic Games StorePublisher StoreSteam
ServicesPublisher Game ServicesPublisher Game ServicesPublisher Game Services
SocialPublisher Account ServicesPublisher Account ServicesPublisher Account Services
StoreEpic Games StorePublisherSteam

Bifurcated Social Graph

In a bifurcated social graph, the primary social graph is the one provided by the storefront the game client was purchased on. However, a bifurcated social graph allows a user to be signed in on more than one social graph at the same time. In-game UI or SDK-based overlays provide the UX for the “Away” social graph to present itself in-game.

Bifurcated social graphs should feature a single matchmaking pool across all platforms, by default.

Pros
  • Best UX – for users, combines simplicity of the “home” social graph with the flexibility of adding the “away” “social graph

  • Largest social graphs – allow users to target the union of the large platform-based social graphs all at once

Cons
  • Non-trivial to implement – less expensive than building and maintaining a publisher social graph; requires some care in UX design and implementation across multiple client versions of the title

  • Multiple identities – users will be left with some of the burden of managing their experience across multiple social graphs; for example: knowing which graph a particular friend is on or what their username is on that social graph

  • Non-linked safety concerns – if a user does not link to the “away” graph and they encounter users from the “away” graph who are abusive, the user may not have immediate recourse to, for example, block that abusive user

  • Steam blockers – Steam does not, as of this writing, allow for account linking to a Steam ID outside the Steam ecosystem. This necessitates signing-in to a Steam account directly every time the game client wants to update the Steam social graph, for example. We encourage developers to request that Steam open up their social graph and services from outside the Steam launcher and Steam clients.

Additional Options
  • Integrated friends – optionally link with other social graphs, including other publisher- or platform-based social graphs where and when available, to display additional friends lists in-game

  • Suggested friends – optionally link to another account to suggest Epic Account Services friends to another social graph

  • Reciprocal friends – optionally link to another account to have Epic Account Services receive friend suggestions from another social graph

  • Remove cross-play – Because bifurcated social graphs should include cross-play ​by default​ in matchmaking, and because situations can arise around abusive players when the user has not linked to the other social graph, the game ​may ​present an option to the user to remove themselves from cross-platform matchmaking. Epic prefers the game instead to present options for dealing with potentially abusive cross-play players versus limiting a user’s matchmaking pool.

Typical Tech Stack

Typically, a game client leveraging a bifurcated social graph across storefronts would use a cross-platform set of multiplayer services (either their own in-house services, EOS, or another third-party solution). In-house solution shown for illustrative purposes in table below. This is not a requirement.

StorefrontEpic Games StoreSteamPublisher Store
ServicesPublisher Game ServicesPublisher Game ServicesNot applicable
SocialEpic Account Services; Steam (optional link - not available yet)Steam; Epic Account Services (optional link)Not applicable
StoreEpic Games StoreSteamNot applicable