# How to port a game > A port is a project with a known answer. Confirm rights, inventory assets, build a slice, then handle input, saves, performance, and the store. - URL: https://www.summerengine.com/how-to-port-a-game - Keyword: how to port a game - Related: https://www.summerengine.com/porting Porting a game means rebuilding or re-targeting a game you own so it runs on a new engine or platform. It is not an automatic conversion, and every real port follows roughly the same eight steps in the same order. The order matters more than the tools. Teams that rebuild content before systems redo the content. Teams that leave input and saves until the end discover the design does not fit the platform. Teams that skip the rights check find out at the store submission stage, which is the most expensive possible time. Summer Engine is built for the rebuild path. Describe systems in plain language, get working scenes and scripts, then edit the real project in C++ or GDScript, with C# available in the desktop editor. One project exports desktop builds for Steam and itch.io, and you own it with no royalties. ## Steps one to three, rights, inventory, and target First confirm you hold the rights to the design, the code, the art, and the audio, including anything bought from a marketplace or bundled with an engine. Second, inventory the assets: what exists in source format, what only exists inside a build, and what must be replaced. Third, choose the target and be specific, because Steam, iOS, Switch, and web impose different input, size, and certification requirements that change the design. ## Steps four and five, the slice and the numbers Fourth, build a vertical slice: player controller, one level, one enemy, pause menu, and save file. That proves the plan and produces a real schedule. Fifth, extract the numbers from the original: movement speed, gravity, jump height, damage, cooldowns, spawn rates, and animation timings. Copy them exactly. A rebuild that feels wrong is almost always a rebuild where values were estimated instead of read. ## Steps six and seven, input and saves Sixth, rework input for the target rather than remapping it. Touch is not a gamepad, a gamepad is not a mouse, and console UI needs focus navigation with no cursor. Seventh, redo saves: write to the platform user directory, save on focus loss for mobile and handheld, handle corruption, and plan whether old saves migrate. Both of these are cheap to do early and very expensive to retrofit. ## Step eight, performance and submission Eighth, profile on the weakest device you intend to support and measure sustained frame rate over several minutes, not the first thirty seconds. Then handle the store: Steam needs a partner account, a 100 USD app fee, and a store page live two weeks ahead. Apple needs a 99 USD per year membership, a Mac, and review. Google needs a 25 USD registration, an app bundle, and a current target API. Console needs approval before anything else. ## FAQ ### Can a game be ported automatically? No. Asset files convert between formats, but game logic, scenes, and editor data are engine specific. Every real port is a rebuild guided by the original as a specification. ### How long does porting take? It scales with systems and platform requirements, not with hours of content. A small game is often a few weeks. A large one is months. The vertical slice converts the guess into a schedule. ### What is the most common mistake? Leaving input and save systems until the end. Both shape the design, and retrofitting touch controls or platform save rules late usually forces UI and progression changes. ### Do I need the original source code? It helps enormously because it holds the exact values, but it is not strictly required if you own the game. Video of the original, the asset files, and careful measurement can reconstruct the behavior. ### Can I port a game I bought but did not make? No. Owning a copy is not owning the rights. Port games you created or ones you hold a clear written license to remake and distribute. ### Which platform should I port to first? Usually Steam, because access is open, the fee is small, and a desktop build is the base for later mobile and console work. Console needs platform approval, so it comes last for most teams. [Start the rebuild](https://www.summerengine.com/download) --- ## Machine-readable resources - Site index for agents: https://www.summerengine.com/llms.txt - Full inlined content: https://www.summerengine.com/llms-full.txt - Porting catalog: https://www.summerengine.com/llms-porting.txt - Structured catalog: https://www.summerengine.com/agent-catalog.json - Sitemap: https://www.summerengine.com/sitemap.xml - Developer resources: https://www.summerengine.com/docs - Summer API (assets from any agent or code; public per-call model prices): https://docs.summerengine.com/api