Install OpenSmash-Ultimate on PC

Before you start: folder rules & the 13.0.5 check

OpenSmash-Ultimate compiles a native executable on your own computer from your own legally dumped copy of Super Smash Bros. Ultimate. Before launching the installer, verify these four inputs:

Why version 13.0.5 is mandatory: tools/game_version.py verifies three signatures during setup and launch: main’s build ID (21450C647B8C5940ED5B68218EA128FD3C5D597D), the update’s title version (0x1F0000, v31), and data.arc’s version field (0xD0005). If your folder contains 1.0.0 alone or an older update such as 11.0.0, the setup line turns red and waits until you place the 13.0.5 update beside the base game and click Check files.

Method 1: Windows 10 & 11 setup via OpenSmash-Setup.exe (Recommended)

1. Download & verify: Grab OpenSmash-Setup.exe (72.4 MB) from v0.3.0-alpha.3 and confirm its SHA-256 on the download page.
2. Choose destination: Run OpenSmash-Setup.exe. If Windows SmartScreen warns about an unrecognized publisher, choose More info → Run anyway. Pick a folder with ~60 GB free (for example C:\OpenSmash) and click Download and set up. It fetches the latest OpenSmash-Ultimate/OpenSmash-Ultimate tree (~20 MB), copies OpenSmash.exe into it, creates OpenSmash and Play SSBU shortcuts, and opens the installer view.
3. Point to your files: The installer automatically checks standard local Switch tool directories and displays what it found underneath Game files, Keys, and Firmware. Use Browse to adjust any path, enter your online Username, and click Check files to confirm the green 13.0.5 status.
4. Configure build options: On the right panel, keep the Windows Firewall rule checked if you plan to play online, select shader preparation priority (low, medium, or high), accept Microsoft’s license terms for the ~570 MB Clang + Windows SDK download, and adjust compiler jobs (fewer jobs keep your desktop responsive on 8 GB PCs).
5. Set up and build: Click Set up and build. First-time compilation takes 30 minutes to a few hours depending on CPU core count. Prevent the PC from sleeping; if interrupted, simply run OpenSmash.exe again and it resumes where it stopped.
6. Play & update: Press Play in the launcher (or use the Play SSBU shortcut). Later updates pull straight from GitHub’s main branch via Settings → Update without touching your save or settings.

Method 2: Linux & Steam Deck Game Mode setup

On 64-bit Linux (glibc 2.35+: Ubuntu 22.04+, Debian 12+, Fedora 36+, Arch, Bazzite, and SteamOS), OpenSmash provides both a local web-app launcher window (opensmash-launcher.sh) and a one-command shell installer (install-windowsmash.sh):

1. SteamOS / Bazzite preparation: Switch to Desktop Mode first. On a Steam Deck, open Konsole and run sudo steamos-readonly disable (and passwd if the deck account has no password; if pacman reports an uninitialized keyring, run sudo pacman-key --init && sudo pacman-key --populate archlinux holo).
2. Unpack in your home folder: Download the repository ZIP from OpenSmash-Ultimate/OpenSmash-Ultimate into ~/WindowSmash (need ~30 GB free space) and run bash opensmash-launcher.sh (or bash install-windowsmash.sh).
3. Automated toolchain & DXVK fetch: The script installs clang, lld, bison, flex, SDL2, libopus, libvpx, Vulkan loader, and zenity, creates deps/venv, and downloads DXVK 3.1.1 and vkd3d 2.1 (each verified against its SHA-256) before compiling build-linux/ssbu.
4. Add to Steam Game Mode: In Desktop Mode Steam, choose Games → Add a Non-Steam Game to My Library, tick OpenSmash Launcher, and switch back to Game Mode. The launcher supports full gamepad controls (D-pad/Left Stick to move, A select, B back, LB/RB switch tabs, Start Play).
5. Optional 65,000-shader DXVK warm pass: Run bash launchers/prepare-shaders.sh in Desktop Mode to compile shaders and run build-linux/ssbu --warm-shaders dump/shadercache so DXVK and Mesa RADV build Vulkan pipelines ahead of matches.

Method 3: Apple silicon macOS 14.5+ setup

1. Unpack outside iCloud folders: Extract the repository into ~/WindowSmash (avoid Desktop, Documents, and Downloads so iCloud Drive does not sync ~30 GB of build artifacts; ~40 GB free required on an APFS volume).
2. Approve Gatekeeper once: Double-click Install WindowSmash.command. When macOS blocks the unsigned script, open System Settings → Privacy & Security, click Open Anyway, and confirm with Touch ID or password (or run bash ~/WindowSmash/"Install WindowSmash.command" directly in Terminal).
3. Build WindowSmash.app: The script verifies Apple silicon (M1 or newer; Intel Macs are unsupported), prompts macOS for Command Line Tools 16+ (macOS 15+ SDK required for Metal features), sets up an isolated arm64 Python + SDL3.framework, and compiles build-mac/WindowSmash.app plus ~/Applications/Play SSBU.app.
4. Exclude build cache from Time Machine: Inside ~/WindowSmash, run tmutil addexclusion build build-mac deps so Time Machine backs up save/ without copying 30 GB of regenerable object files.

Moving large data folders, importing saves & adding Miis

• Relocate dump/ and build/ to another drive: Close the game and launcher, then run python tools\data_location.py --move D:\OpenSmash. It moves the heavy directories and leaves directory links in place.
• Import existing Switch saves: Close the game first. Unified/WindowSmash builds store saves in save\; standalone ssbu-recomp builds use build\saves\save\save_data\system_data.bin. Back up the existing folder before copying your own save directory in.
• Import custom Miis: Double-click launchers\Import Miis.bat (or launchers/Import Miis.command on macOS) to import existing local Mii databases, drop .charinfo / .nfsd / .nfcd files, or paste Mii Studio image URLs (up to 100 Miis stored in miis\).

Installed directory layout reference