Photon Quantum

Photon Quantum is a deterministic ECS framework for Unity online multiplayer games, with sessions listed for up to 128 players. Clients exchange player inputs and predict other players’ inputs locally; when a prediction is wrong, the game restores and resimulates state. Quantum separates simulation from presentation, using Unity for editor tooling and the view layer. Its deterministic libraries cover math, 2D and 3D physics, navigation, animation and bots. Photon Realtime transport and Photon server infrastructure synchronize clocks and manage input latency. Developers can extend the server component to connect customer-hosted services such as matchmaking, player services and referee simulations. Quantum 3 webhooks support room control, configuration and player-data validation, and sending match replays to a configured endpoint. Free plans include development access for 20 connected users or a games-only plan for 100. Paid plans include 100 CCU for $95 once for 12 months and 500 CCU for $125 a month. Photon Engine states it is ISO 27001:2022 certified.

Quantum provides a deterministic simulation framework with rollback and server infrastructure for Unity multiplayer games. Its free and paid options differ in connected-user limits and usage terms, while the custom server SDK requires specified membership.

It suits Unity developers building online multiplayer games that use deterministic simulation and rollback. The server extension and webhooks may also suit teams integrating their own matchmaking, player services or referee simulations.

Photon Quantum is a Unity framework for building online multiplayer games around deterministic simulation and rollback. It suits teams that need input-based synchronization and Photon-hosted networking, especially for games where correcting mistaken predictions matters. Its simulation and server integration options are substantial, but connected-user caps and the custom-server SDK’s membership requirement shape who should choose it.

Overview

Quantum uses a client-server model in which clients exchange player inputs, predict other players’ actions, and restore and rerun the simulation when those predictions prove wrong. That approach can keep play responsive while correcting divergent states, but it puts deterministic simulation at the center of the game architecture rather than treating networking as a simple add-on.

Unity provides the editor tools and presentation layer; Quantum handles the separate simulation. Its documented libraries cover math, 2D and 3D physics, navigation, animation, and bots. Photon Realtime transport and Photon server infrastructure synchronize clocks and manage input latency. The framework supports matchmaking, offers UDP, TCP, WebSocket, and Secure WebSocket transports, and is listed for sessions of up to 128 players.

Teams can extend the server component to connect customer-hosted matchmaking, player services, or referee simulations. Quantum 3 webhooks support room control, configuration and player-data validation, and sending full match replays to a configurable endpoint. Photon says deterministic gameplay and exchanging inputs help resist cheating; replay validation and server referee simulations provide additional anti-cheat approaches. Photon Engine states that it is ISO 27001:2022 certified.

Key features

• Prediction and rollback: Clients simulate likely inputs locally, then restore and resimulate when actual inputs differ. This suits games that need responsive client simulation with correction, though it requires a deterministic simulation design.
• Simulation separate from presentation: Unity remains the editor and view layer while Quantum runs simulation logic. That separation helps teams build around deterministic systems rather than coupling game state to presentation.
• Built-in simulation libraries: Math, physics, navigation, animation, and bots provide core simulation capabilities in one framework, reducing the need to assemble those areas independently.
• Server and backend extensibility: Customer-hosted services can connect to the server component, and Quantum 3 webhooks add room control, data validation, and replay delivery. The Quantum Plugin SDK for creating and locally testing a custom server for Photon Enterprise Cloud requires Gaming Circle or Industries Circle membership.
• Web sample: Photon provides a Unity WebGL sample integrated with CrazySDK from Crazy Games, a useful starting point for teams targeting that web-game context.

Pricing

Quantum is freemium, with free options for development and smaller games, plus paid fixed-capacity and usage-based cloud plans. The free plans cap connected users and traffic and do not include CCU bursts; the paid plans add capacity, and some add burst handling or automatic scaling.

• Development Only 20 CCU — free: 20 connected users and 60.0 GB traffic per month, development only, with no CCU burst. It is appropriate for development, not a live game.
• Free 100 CCU — free: 100 connected users, one app per customer, games only, approximately 40k MAU, and 0.3 TB traffic per month, with no CCU burst. It offers a no-cost route for a small game, but the app, traffic, and capacity limits constrain growth.
• 100 CCU — $95, paid once: One-time payment for 12 months, with 100 connected users, games only, approximately 40k MAU, and 0.3 TB traffic per month; no CCU burst. It retains the free tier’s listed capacity and traffic ceiling, so its appeal is a 12-month paid term rather than more headroom.
• 500 CCU — $125 a month: 500 connected users, approximately 200k MAU, and 1.5 TB traffic per month, with CCU burst included. This is a more capable monthly step for games outgrowing the 100-user plans.
• 1000 CCU — $250 a month: 1,000 connected users, approximately 400k MAU, and 3.0 TB traffic per month, with CCU burst included.
• 2000 CCU — $500 a month: 2,000 connected users, approximately 800k MAU, and 6.0 TB traffic per month, with CCU burst included.
• Premium Cloud — $0.50 a month: Invoiced based on monthly usage, with a $1,000 minimum fee per month, a 2,000 CCU minimum, 6.0 TB traffic included, usage-based CCU auto-scaling, and default DDoS protection. The low per-CCU figure does not make this a low-cost entry plan: the minimum monthly fee and capacity floor target larger operations.
• Enterprise Cloud — custom pricing: A dedicated managed cloud environment with unlimited titles, SLA, priority operations support, dedicated servers, server-authoritative logic via plug-ins, and multi-layered DDoS protection. Its operational and server-authoritative provisions make it the option for teams needing a managed dedicated environment, rather than a small project.

Free plans include online documentation, samples, tutorials, video streams, and help with account and billing matters. Gaming Circle offers premium development support. The Plugin SDK’s membership gate is particularly important for teams that intend to build and locally test a custom server for Photon Enterprise Cloud.

Platforms

Quantum’s listed platforms include Windows, macOS, Android, iOS, WebGL, Nintendo Switch, Xbox One, Xbox Series X|S, PS4, and PS5. The platform breadth makes it relevant to cross-platform Unity projects; the WebGL sample offers a concrete web-targeting example. Android, iOS, Linux, macOS, web, and Windows are also listed as platforms for the product.

Who it's for

Quantum is best suited to Unity teams building multiplayer games that benefit from deterministic simulation, prediction, and rollback, and that want Photon’s networking infrastructure alongside room for custom backend services. Smaller teams can start with development or free capacity, while games with higher concurrency can move to paid plans with larger limits and, on applicable tiers, CCU bursts.

It is a weaker fit for a project that needs uncapped free concurrency, or for a team that must create a custom Photon Enterprise Cloud server without Gaming Circle or Industries Circle membership. Teams that do not want Photon-hosted infrastructure should compare self-hosting or open-source alternatives.

Pros and cons

Pros

• Rollback is central to the framework: Input prediction and resimulation are built into its stated networking model, making it a focused option for games that need that approach.
• Simulation tools span multiple systems: Documented libraries cover physics, navigation, animation, math, and bots, alongside the deterministic simulation.
• Room for backend and anti-cheat integration: Server extensions and Quantum 3 webhooks support external services, validation, replay delivery, and referee simulations.
• Free entry points: Development and 100-CCU options let teams begin without a plan charge, though the latter is constrained by traffic and app limits.

Cons

• Free capacity is bounded: The free plans cap at 20 or 100 connected users, have traffic limits, and exclude CCU bursts; the 20-user plan is development-only.
• Custom server creation has a membership gate: The Plugin SDK requires Gaming Circle or Industries Circle, which limits access to a notable extension path.
• Premium Cloud has a substantial minimum commitment: Its $1,000 minimum monthly fee and 2,000-CCU floor make it unsuitable as a modest step up from free.
• 100 CCU does not raise the free tier’s stated ceiling: At $95 for 12 months, it still provides 100 connected users and 0.3 TB traffic monthly, without bursts.

Alternatives

Game Networking Middleware is the broader category list for comparing networking options.

• Photon Fusion is another Photon freemium option with a free 100-CCU plan for one game app, approximately 40k MAU, and 0.3 TB monthly traffic; compare it if you want a Photon alternative at that free capacity.
• Photon Realtime has a free development plan for 20 concurrent users and 60.0 GB monthly traffic; consider it if that development-scale free allowance fits your needs.
• Colyseus offers an open-source self-hosted plan with community support and no restrictions, making it a candidate when self-hosting and unrestricted plan terms matter more than Quantum’s Photon cloud structure.
• FishNet is a free Unity networking solution with no CCU caps or CCU paywalls; consider it if avoiding connected-user limits is the priority.
• GameNetworkingSockets is a free open-source library under a BSD-3-Clause license; its Steam Datagram Relay access is restricted.
• Mirror Networking is free and open source under MIT, with no paywalls or CCU costs, making it an alternative for teams seeking those terms.
• Netcode for GameObjects is a free Unity package that requires a valid Unity account and license and Unity Editor 2021.3 or later; consider it if that Unity-package model suits the project.
• Netick has a free plan for server-authoritative state-sync networking for Unity, while Interest Management and Lag Compensation are Pro features.

Verdict

Choose Photon Quantum for a Unity multiplayer game whose core needs are deterministic simulation, rollback, and Photon-backed networking, with backend integration available as the game grows. Its strongest case is the combination of simulation libraries, input correction, and server extensibility. Look elsewhere if uncapped free concurrency or unrestricted custom-server development is essential, or if Premium Cloud’s minimum commitment does not fit the project.