Launch keys

Every setting a launch reads, as universe launch-keys lists them. A game’s own value, set in its Game settings or with universe set <game> key=value, wins over the default every game shares, set in Settings or with universe config set launch.key value. Launch settings explains how the pages show them.

Display

Gamescope

Run the game in a window of its own, at the resolution and refresh rate below; a launcher already inside gamescope puts it on that one instead.

Key gamescope · default true. Set per game, over a default in Settings › Game defaults.

Resolution

What the game renders at; auto is the screen’s own. A lower one is upscaled to the screen, lighter on the GPU.

Key gamescope_resolution · default auto · such as auto, 1920x1080, 1280x720. Set per game, over a default in Settings › Game defaults.

Refresh rate

The refresh rate the game sees; auto is the screen’s own.

Key gamescope_refresh · default auto · such as auto, 240, 165, 144. Set per game, over a default in Settings › Game defaults.

Adaptive sync

Variable refresh rate (FreeSync, G-Sync): no tearing, no stutter below the refresh rate. Auto turns it on when the screen supports it.

Key gamescope_adaptive_sync · default auto · one of auto, on, off. Set per game, over a default in Settings › Game defaults.

Overlay

Show MangoHud

Draw the overlay (frame rate, frame time, GPU and CPU load) over the game from launch. Off keeps MangoHud loaded but hidden, the frame rate limit still holds. The in-game menu or the pad macro shows or hides it for the running game alone: the next launch starts from here again.

Key mangohud · default false. Set per game, over a default in Settings › Game defaults.

Frame rate limit

MangoHud holds the game to this many frames per second, overlay or not; auto is the refresh rate the game sees, and no limit for an emulator, which paces itself. The in-game menu changes it for the running game alone.

Key fps_limit · default auto · such as auto, none, 240, 165. Set per game, over a default in Settings › Game defaults.

Pause on HOME

Freeze the game while the launcher covers it, so the pad drives the menu alone; it runs again on Resume. Off for a game that must keep running (online play).

Key pause_on_home · default true. Set per game, over a default in Settings › Game defaults.

Scaling

Scaler

How a smaller picture fills the screen: integer keeps pixels whole, fit keeps the aspect, fill and stretch do not.

Key gamescope_scaler · default "" · one of auto, integer, fit, fill, stretch. Set per game, over a default in Settings › Game defaults. Shown with Show advanced.

Filter

The upscaling filter: fsr and nis sharpen, nearest and pixel keep pixel art crisp. The in-game menu changes it for the running game alone.

Key gamescope_filter · default "" · one of linear, nearest, fsr, nis, pixel. Set per game, over a default in Settings › Game defaults. Shown with Show advanced.

Sharpness

For fsr and nis: 0 is sharpest, 20 softest. The in-game menu changes it for the running game alone.

Key gamescope_sharpness · default null · such as 0, 2, 5, 10. Set per game, over a default in Settings › Game defaults. Shown with Show advanced.

Gamescope arguments

Extra gamescope flags, after and over the fields above.

Key gamescope_args · default "". Set per game, over a default in Settings › Game defaults. Shown with Show advanced.

Discrete GPU

On a laptop with two GPUs, the game and gamescope render on the stronger one rather than the one driving the screen. Off leaves the choice to the system. Nothing changes on a machine with one GPU.

Key discrete_gpu · default true. Set per game, over a default in Settings › Game defaults. Shown with Show advanced.

Environment

Environment variables

Environment variables for the game; a game’s win over the global ones.

Key env · default "". Set per game, over a default in Settings › Game defaults. Shown with Show advanced.

Launch

Wrapper command

A command the game runs through, innermost: gamemoderun, taskset -c 0-7…

Key wrapper · default "". Set per game, in its Game settings. Shown with Show advanced.

Arguments

Arguments appended to the game’s command line.

Key args · default "". Set per game, in its Game settings. Shown with Show advanced.

Working directory

The folder the game starts in.

Key working_dir · default "". Set per game, in its Game settings. Shown with Show advanced.

Before the game

A shell line run before the game starts.

Key pre_command · default "". Set per game, in its Game settings. Shown with Show advanced.

After the game

A shell line run once the game has ended.

Key post_command · default "". Set per game, in its Game settings. Shown with Show advanced.

Proton

Proton build

The Proton build umu-run starts the game with.

Key proton · default proton-ge. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it.

Wayland

Proton’s own Wayland driver instead of Xwayland: lower latency, proper scaling; dropped inside gamescope unless it exposes Wayland.

Key wayland · default true. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it.

HDR

HDR output on an HDR screen: Proton’s PROTON_ENABLE_HDR, and –hdr-enabled on gamescope.

Key hdr · default false. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it.

PlayStation controller

How GE-Proton hands a PlayStation controller to a Windows game. Native keeps its buttons and haptics, but a game made for Xbox pads sees nothing; an Xbox pad works in any game that takes one. Auto goes by the game’s Steam page.

Key sony_pad · default auto · one of auto, native, dualshock4, xinput. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it.

Wine prefix

The Wine prefix the game runs in; empty: <prefixes_root>/<id>.

Key prefix · default "". Set per game, in its Game settings. Only Proton and Wine games read it. Shown with Show advanced.

Architecture

WINEARCH for a plain Wine prefix.

Key arch · default win64 · one of win64, win32. Set per game, in its Game settings. Only Wine games read it. Shown with Show advanced.

umu id

GAMEID for umu-run’s protonfixes; empty: umu-<Steam app id> when the game has one, else umu-default.

Key umu_id · default "". Set per game, in its Game settings. Only Proton games read it. Shown with Show advanced.

Store

STORE for umu-run’s protonfixes.

Key store · default "". Set per game, in its Game settings. Only Proton games read it. Shown with Show advanced.

DLL overrides

WINEDLLOVERRIDES, one key per DLL without .dll: d3d11 = “n,b”.

Key dll_overrides · default "". Set per game, in its Game settings. Only Proton and Wine games read it. Shown with Show advanced.

Sync

Esync

Faster thread synchronisation through eventfd; on for most games, off if one hangs or stutters.

Key esync · default true. Set per game, over a default in Settings › Emulators & Proton › Proton or Wine. Only Proton and Wine games read it. Shown with Show advanced.

Fsync

Faster still, through the kernel’s futex2; takes over from esync when the kernel has it.

Key fsync · default true. Set per game, over a default in Settings › Emulators & Proton › Proton or Wine. Only Proton and Wine games read it. Shown with Show advanced.

NTSync

The kernel’s NT synchronisation driver, the fastest; needs Linux 6.14 and a Proton built for it, else falls back.

Key ntsync · default true. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it. Shown with Show advanced.

Upscaling

DLSS upgrade

Games with DLSS use the newest DLSS from the NVIDIA driver instead of the one they ship. NVIDIA GeForce RTX only; auto turns it on there. A swapped DLL can upset a game or an anti-cheat.

Key dlss_upgrade · default off · one of auto, on, off. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it. Shown with Show advanced.

FSR 4 upgrade

Games with FSR 3.1 use FSR 4 instead, sharper and cleaner. Radeon RX 9000 (RDNA 4), where auto turns it on, or RX 7000 (RDNA 3) at a cost, through Proton’s RDNA 3 variant picked for it. A swapped DLL can upset a game or an anti-cheat.

Key fsr4_upgrade · default off · one of auto, on, off. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it. Shown with Show advanced.

XeSS upgrade

Games with XeSS use the newest XeSS instead of the one they ship. Any GPU; best on Intel Arc, where auto turns it on. A swapped DLL can upset a game or an anti-cheat.

Key xess_upgrade · default off · one of auto, on, off. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it. Shown with Show advanced.

OptiScaler

Adds FSR 4 or XeSS to games that only offer DLSS, through OptiScaler. For AMD and Intel; needs a Proton that ships it (CachyOS, GE).

Key optiscaler · default false. Set per game, over a default in Settings › Emulators & Proton › Proton. Only Proton games read it. Shown with Show advanced.

Logs

Debug log

Proton, Wine and DXVK write their full logs for each session, kept with the game’s own under Sessions. Large; on for a game that misbehaves.

Key debug_log · default false. Set per game, over a default in Settings › Emulators & Proton › Proton or Wine. Only Proton and Wine games read it. Shown with Show advanced.

Programs

Gamescope program

The gamescope binary: a name on PATH or a path.

Key gamescope_bin · default gamescope. Set for every game, in Settings › Game defaults. Shown with Show advanced.

umu-run program

The umu-run binary: a name on PATH or a path.

Key umu_run · default umu-run. Set for every game, in Settings › Game defaults. Shown with Show advanced.