Client-Server Game Architecture
Unknown
Gabriel Gambetta's four-part article series on fast-paced multiplayer networking: authoritative servers, client-side prediction, server reconciliation, entity interpolation and lag compensation, with a live interactive demo. Readers come away understanding why online shooters feel responsive despite latency and how to implement it.
More resources on Multiplayer Game Development
Unity Netcode for GameObjects Documentation
Unity's official documentation for Netcode for GameObjects, its high-level networking library: NetworkObjects, NetworkVariables, RPCs, ownership, scene management and transports, with sample projects. After working through it you can add synchronized multiplayer to a Unity game and reason about server authority.
Multiplayer Game Programming
Textbook on building networked games from the socket level up: object serialization, replication, client-side prediction, latency hiding, scalability, security and cloud hosting, illustrated with C++ sample games. Readers learn to design and implement the networking layer of a real-time multiplayer game.
photonengine.com
Photon Engine provides a cloud-based real-time multiplayer networking platform for games, with SDKs and tools for popular engines to build, host, and scale multiplayer experiences. The site offers product pages (Realtime, Fusion, Quantum), extensive documentation, tutorials, sample projects, demos, pricing, and other developer resources.
Developing Online Games
Industry veterans' guide to the business and operations side of online and massively multiplayer games: budgeting, team building, launch, live operations and community management, with case studies and insider interviews. Readers understand why online games succeed or fail beyond the code.
GameDev.net
Long-running game development community with forums, member blogs, tutorials and articles on programming, graphics, physics, art, audio and design, where developers can ask technical questions, study worked techniques and follow discussion of how games are built.