OpenSmash-Ultimate

OpenSmash-Ultimate

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OpenSmash-Ultimate turns Super Smash Bros. Ultimate into a native PC program by static recompilation. It translates the game's ARM64 code into C once, ahead of time, compiles it, and links it with a runtime that stands in for the Nintendo Switch. The game's code and data come from a copy you dumped from your own console.

It is the merge of two projects, WindowSmash and ssbu-recomp: one repository, one runtime (WindowSmash's, at game version 13.0.5) and one community. New work, issues and pull requests go here; the two old repositories are kept for their history.

Install

1. Download OpenSmash Setup.exe from the latest release and run it. It does the rest.
2. Choose where OpenSmash goes (about 60 GB free; not the Desktop or Documents) and click Download and set up. It downloads the project from GitHub into that folder, makes the OpenSmash and Play SSBU shortcuts (desktop and Start menu), and opens the launcher there.
3. In the installer window, check that it found your game files (game plus its 13.0.5 update), keys and optionally firmware; fix any folder with Browse. Click Set up and build and wait: 30 minutes to a few hours.
4. Press Play in the launcher, or use the Play SSBU shortcut.
5. To update, open Settings -> Update in the launcher. Mods are in the launcher's Mods view; online is in Settings -> Online.

You need your own copy of the game, version 13.0.5, dumped from your own Switch, and a 64-bit Windows 10 or 11 PC; AVX2 is recommended, SSE4.2 works too. Linux and macOS (Apple silicon) are experimental. The installation guide explains each step; docs/BUILDING.md is the step-by-step setup and building from source.

What's in it

Area	What you get	Where
The game	The whole game recompiled for x86-64: menus, every mode, DLC fighters and stages, movies (VP9), music.	here
Online	Rooms with a code (XXXXX-XXXXX), LAN rooms, a lobby, relay and direct paths; rollback netplay for fights (SSBU_RB, from WindowSmash #103 and ssbu-recomp #116).	#55, #59, #63
Mods	The OpenSmash launcher and mod manager, Skyline plugins, ARCropolis mods, a switch for every mod in the game's settings and in the launcher; native mods written against hook.h.	#62, #63, #67
New fighters	Fighters with a kind and files of their own (up to 16), all eight colours; fighters written as C++ source.	#67, #68
Graphics	Direct3D 11 by default; Vulkan as a choice in display.ini and the settings menu; Metal on macOS; shader prewarm and Prepare Shaders.	#64, #26
Settings	Game language, master volume, controllers (dead zones, invert, ignore), GameCube adapters, keyboard keys, low-latency display mode, the album.	#56, #57, #60, #3
Memory	Caps on the shader prewarm and on the copy kept for mod reloads; a memory line in the log.	#66

Rows that link to pull requests are being reviewed and land in main as they are merged.

Guides

Guide	Read it to
Installation guide	install, update, add mods and go online.
Setup guide	do every setup step by hand, and build from source.
Playing	change the controls or the window, and find saves, screenshots and problem reports.
Multiplayer	play with other people online or in a private room.
Mods and Skyline plugins	install mods and plugins and turn them on or off.
DLC and unlocks	use your DLC, or unlock every base-game fighter on your save.
The 13.0.5 update	see which copies of the game count as 13.0.5 and how the update is applied.
Linux · macOS	install, build and run the experimental versions.
How it works	understand the recompiler, the runtime and every tool.

ssbu-recomp/

ssbu-recomp/ holds ssbu-recomp as it was imported, with its history, so git log and git blame still show who wrote what. Its parts move out of the folder as they are ported to the root runtime, and the folder goes when it is empty. Material taken from the game was removed from every commit of its history on import.

Getting help

• Questions and finding players: the OpenSmash-Ultimate Discord, discord.gg/pkgyYGf3YB (WindowSmash's and ssbu-recomp's communities in one server).
• Setup problems: see If something goes wrong in the setup guide.
• Bugs: open an issue with your operating system, graphics card and driver version, what you did, what happened instead, and the end of the log (build/play.log, plus the .txt report from reports/ after a crash).
• Security problems: report them privately, as SECURITY.md explains. Don't open a public issue.

For developers

Read CONTRIBUTING.md first. Its three rules hold for every change: nothing derived from the game goes into the repository, clean sources only, and every claim is measured.

WindowSmash's source-only tests use made-up data and need no game files. Run them from the repository root, in PowerShell or a Unix shell:

python -m pip install -r tests/requirements-dev.txt
python -m unittest discover -s tests -v
cd tools
python -m nex.selftest

CI runs these workflows from .github/workflows/:

Workflow	Runs on	What it checks
WindowSmash tests	Windows, Linux, macOS	The unit tests and the NEX server self-test.
Runtime compile	Windows, Linux, macOS	The whole runtime, with its platform layer, compiles and links into the game's program as a player's build makes it, on a made-up game (tools/dev/runtime_compile_check.py); on Windows and Linux for both instruction sets. Every runtime source is in the program unless the script lists it as left out on purpose, and none is in a subfolder no build looks in.
ssbu-recomp Linux runtime	Linux	ssbu-recomp's host runtime compiles; its synthetic differential test, platform self-test and compile-scheduler test pass; setup.py --tools-only finds every tool and library the build needs; its log collector leaves game files out of a report. Its installer script, install_deps.sh, is only checked for syntax: the workflow installs the packages itself.
ssbu-recomp macOS runtime	macOS (Apple silicon)	The same on macOS, where install_mac.sh does run. It also builds the glslang shim, checks that setup.py stops at the dump check when given an empty dump, and reports what MoltenVK offers on the runner.
No game data	Linux	No Switch files (.nca, .nsp, .nsz, .xci, .nso, .nro, .arc), no key files, and no file over 10 MB, in any commit.

License

OpenSmash-Ultimate is free software under the GNU General Public License, version 3 or (at your option) any later version: GPL-3.0-or-later. LICENSE holds the license text. Third-party parts keep their own licenses, listed in NOTICE.md.

The license covers this project's own source. It gives no rights to Super Smash Bros. Ultimate, its files, or anything built from them.

Super Smash Bros. Ultimate and related names belong to their respective owners. OpenSmash-Ultimate is an independent project and is not affiliated with or endorsed by Nintendo.