# Port a 3DS game by rebuilding it, not converting it > Porting a 3DS game means rebuilding a game you own as a new project that runs on platforms that still sell games. There is no file converter for this. - URL: https://www.summerengine.com/port-a-3ds-game - Keyword: port a 3ds game - Related: https://www.summerengine.com/porting Porting a 3DS game means rebuilding a game you own as a new project in a current engine, then exporting that project as a desktop build for Steam and itch.io. It is not a format conversion. No tool reads a 3DS build and produces a PC game. You need the rights. That means you made the game, or you hold a license to remake it. Owning a cartridge is not a license. This page does not cover ROM dumping, ripping assets, or wrapping an emulator. Summer Engine is where the rebuild happens. You describe the original scenes and systems, the engine generates a working project, and you keep editing it in C++, GDScript, or C#. The workflows are compatible with Godot 4, we always follow Godot upstream, and Summer is a fully custom engine with more than a million lines of custom code. You own the project and pay no royalties. ## What actually carries over from a 3DS project Your art sources carry over: sprite sheets, textures, models, audio files, fonts. Your design carries over: level layouts, enemy tables, dialogue, balance numbers. Your old code carries over as reference, not as a drop-in. The 3DS used a PICA200 GPU and a Nintendo toolchain, so rendering code, input code, and file loading are rewritten. Most teams rebuild systems in order: player controller, camera, one level, then the UI. ## The two screens are the main design decision The 3DS top screen is 400x240. The bottom touch screen is 320x240. A single-display port needs one of three layouts. Stack both screens vertically and letterbox the result. Promote the top screen to full screen and convert the bottom screen into a HUD overlay or a toggled panel. Or split them across a phone screen, where the touch layer still works as designed. Map stylus input to mouse clicks on desktop and to direct touch on mobile. ## Resolution, art, and the stereoscopic layer 3DS art was authored for a small, low-resolution panel. At 1080p or 1440p the seams show. Pixel art holds up with integer scaling and a nearest neighbor filter. Low-polygon models usually need higher resolution textures rather than new geometry. Stereoscopic 3D has no equivalent on a flat display, so the depth budget you built becomes camera parallax, depth of field, or a stronger foreground and background separation. ## Controls after the Circle Pad The original 3DS has one Circle Pad, a d-pad, four face buttons, L and R, and a touch screen. The New 3DS added a C Stick and ZL and ZR. A desktop port gains a second analog stick, so camera control that was on buttons or the touch screen can move to the right stick. Plan for keyboard and mouse, a standard gamepad, and touch, and expose remapping. Every input path needs its own pass on menus, not just gameplay. ## Where the rebuilt game ships The 3DS eShop closed in March 2023, which is why most of these ports exist. From one Summer Engine project you export desktop builds for Windows and macOS, ready for Steam and itch.io. iOS and Android builds need that platform's toolchain and signing and a pass on touch input. A GDScript project also exports a web build for Summer Games, and a console version needs Nintendo approval and certification, usually through a licensed porting partner. You keep all revenue, with no royalties and no revenue share. ## FAQ ### Can you convert a 3DS ROM or CIA file into a PC game? No. No tool converts a 3DS build into a playable project in another engine. A 3DS port is a rebuild from your own source, assets, and design. Summer Engine does not read ROM, CIA, or 3DSX files. ### Is it legal to port a 3DS game I bought? No, not on the basis of buying it. Buying a cartridge or an eShop download gives you a copy, not the rights to rebuild and publish that game. You can legally port a 3DS game you created, or one you hold a written license to remake. ### How do you handle the two 3DS screens on a single display? Three options work. Stack the 400x240 top screen and the 320x240 bottom screen vertically, promote the top screen and turn the bottom screen into a HUD or toggled panel, or keep both screens on a phone where touch input still applies. Most desktop ports promote the top screen. ### Do I need the original 3DS source code to port my game? No, but it helps. Source is useful as a specification for your systems and balance numbers. If it is gone, you can rebuild from the design, the art sources, and recordings of the original game. Rendering and input code is rewritten either way. ### What can I export a ported 3DS game to? Desktop builds for Windows and macOS, which cover Steam and itch.io. Mobile builds need each platform's toolchain and signing, a GDScript project also exports a web build for Summer Games, and console needs platform holder approval. You own the project and pay no royalties. ### How long does a 3DS port take? A playable vertical slice usually takes days. A full port of a shipped 3DS game takes weeks to months, depending on content volume. The screen layout, the control rework, and the UI are what consume the time, not the core gameplay code. [Start your 3DS port](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