In-game Options¶

While playing on a built-in emulator core, press MENU and choose Options to open the in-game options menu. Most changes apply live — you see the result as soon as you return to the game.

The Options menu contains:

Entry	What it's for
Frontend	Video scaling, screen effects, overlays, CPU speed, fast-forward and rewind.
Core Options	The emulator core's own settings — see Emulator Options.
Shaders	The video shader pipeline and shader presets.
Cheats	Turn the game's cheats on and off.
Controls	Remap the emulated controller's buttons.
Shortcuts	Bind in-game hotkeys (save/load state, fast-forward, rewind, turbo…).
Achievements	Browse the game's RetroAchievements — shown only when achievements are enabled.
Save Changes	Keep your changes for this system or this game, or restore defaults.

The Frontend entry shows the NX Redux version next to it, and Core Options shows the running core's version.

Changes aren't saved until you use Save Changes

Everything you change in Options takes effect immediately but only lasts for the current session. To keep it, open Save Changes before you quit. This makes it easy to experiment: to undo a change, quit without saving.

Frontend¶

Settings handled by NX Redux itself rather than the emulator core, so the same list appears for every system. Use LEFT / RIGHT to change a value.

Option	Values	What it does
Screen Scaling	Native, Aspect, Aspect Screen, Fullscreen, Cropped	Native uses integer scaling (sharpest, may leave borders). Aspect fills the screen at the core's reported aspect ratio. Aspect Screen uses the screen's aspect ratio. Fullscreen stretches to fill the screen (non-square pixels). Cropped is integer-scaled and then cropped to fill — only on devices that support it.
Audio Resampling Quality	Low, Medium, High, Max	Higher quality uses more CPU. Default: High.
Ambient Mode	Off, All, Top, FN, LR, Top/LR	Makes the chosen LEDs follow the colors on screen. See also LED Control.
Screen Effect	None, Line, Grid	Grid simulates an LCD grid, Line simulates CRT scanlines. Effects usually look best with Native scaling.
Overlay	None, or any overlay for this system	A border/bezel image drawn around the game — see Overlays.
Offset screen X / Offset screen Y	−64 to +64	Shift the game image horizontally/vertically by this many pixels. Default: 0.
Screen Sharpness	NEAREST, LINEAR	NEAREST keeps pixels crisp; LINEAR smooths lines, and works best when the final image is high resolution (a high-res core, or upscaling with shaders). Default: LINEAR.
Core Sync	Auto, Screen, Native, Emulated	What drives the frame rate: Native follows the emulator's frame rate, Screen follows the display's refresh rate. Emulated follows the game's own timing, for GPU-rendered systems such as Dreamcast (its default); for other systems it behaves like Native. Auto picks for you.
CPU Speed	Powersave, Normal, Performance, Auto	Underclock to save battery or overclock for demanding games. Auto (default) scales within a range tuned for each emulator.
Debug HUD	Off, On	Show frames per second, CPU load, resolution and scaler information on screen.
Max FF Speed	None, 2x – 8x	Cap for fast-forward (it may run slower depending on the game and emulator). Default: 4x.
Fast forward audio	Off, On	Play or mute audio while fast-forwarding. Default: Off.
Rewind	Off, On	Enable the in-memory rewind buffer. Uses extra CPU and memory, and needs a shortcut (Toggle Rewind or Hold Rewind) to use during play. Default: Off.
Rewind Buffer (MB)	8, 16, 32, 64, 128, 256	Memory reserved for rewind snapshots — more memory means you can rewind further back. Default: 64.
Rewind Interval	16 ms (~60 fps) – 600 ms	Time between rewind snapshots. Shorter intervals give smoother rewinding but use more CPU and memory. Default: 16 ms.
Rewind Compression	Off, On	Compress snapshots to fit more into the buffer, at the cost of CPU. Default: On.
Rewind Compression Speed	1 (best ratio) – 12 (fastest)	Lower values compress more but use more CPU. Default: 2.
Rewind audio	Off, On	Play or mute audio while rewinding. Default: Off.

Note

Some systems lock individual frontend options to a fixed value; locked options don't appear in the list.

Shaders¶

Controls the video shader pipeline. If the Shaders/ folder is missing or empty, the menu says so instead.

Option	What it does
Optional Shaders Settings	Opens the extra parameters exposed by the active shaders (e.g. scanline strength). Shows "No extra settings found" when the shaders have none.
Shader / Emulator Settings Preset	Load a ready-made preset from the `Shaders/` folder (`crt-perfect`, `lcd-perfect`, `real-gameboy`, `scanlines`, `old-tv`, pixel-perfect variants and more). Loading a preset replaces your current shader settings — to just try one out, quit without saving.
Number of Shaders	`off`, or 1 to 3 shader passes.
Shader 1–3	The `.glsl` program each pass runs, picked from `Shaders/glsl/`.
Shader 1–3 Filter	Upscaling method for that pass: NEAREST or LINEAR.
Shader 1–3 Source type / Texture Type	Which resolution the pass scales from: `source` or `relative`.
Shader 1–3 Scale	Scale the image 1x–8x, or `screen` to scale to the screen's resolution (can hurt performance).

See Shaders for more about presets.

Cheats¶

Lists every cheat found for the game. Toggle a cheat On / Off with LEFT / RIGHT — it applies immediately. Press A on a cheat to read its full description.

If no cheat file is loaded, the menu lists the file names it looked for and points you at Xtras → Cheat Database. Cheats can't be enabled while RetroAchievements hardcore mode is active. See Cheats for where cheat files go.

Controls¶

Remaps the buttons of the emulated controller to your device's buttons. Only the buttons the running core uses are listed.

Press A on a button, then press the device button (or MENU + button) you want to assign to it.
Press X to clear a binding (NONE).
For cores that support different controller types (for example PlayStation), a Controller entry at the top switches between Standard and DualShock.

Shortcuts¶

Hotkeys for actions during play. All are unbound (NONE) by default. Bind them the same way as Controls: A then the button or MENU + button to set, X to clear. Using a MENU + button combination keeps the shortcut from clashing with the game's own controls.

Shortcut	Action
Save State / Load State	Save to / load from the current save state slot.
Undo Load State	Go back to where you were before the last Load State.
Reset Game	Restart the game.
Save & Quit	Save and exit the game.
Cycle Scaling	Step through the Screen Scaling modes.
Cycle Effect	Step through the Screen Effect modes.
Toggle FF / Hold FF	Fast-forward: toggle on/off, or only while held.
Toggle Rewind / Hold Rewind	Rewind: toggle on/off, or only while held. Needs Rewind turned on.
Game Switcher	Open the Game Switcher.
Screenshot	Take a screenshot.
Toggle Turbo A / B / X / Y / L / L2 / R / R2	Turn turbo (rapid fire) on or off for that button.

Achievements¶

Appears only when RetroAchievements is enabled, with your progress (e.g. 12 / 40 unlocked) next to it. It lists the running game's achievements, sorted by the Achievement sort order setting in RetroAchievements.

A — open an achievement's details.
Y — switch between showing all achievements and only locked ones.
X — mute or unmute notifications for the selected achievement (marked [M]), handy for chatty progress trackers.

If the game isn't recognized or has no achievements, a message tells you so.

Save Changes¶

Keeps what you've changed in Options: Frontend, Core Options, Shaders, Controls and Shortcuts. The entry's description tells you which settings the game is using right now: Using defaults, Using console config or Using game config.

Choice	What it does
Save for console	Save as the defaults for every game on this system (same as Emulator Settings). If this game had its own config, that is removed so the game follows the system settings again.
Save for game	Save for this game only, overriding the system settings (same as Emulator Options in the context menu).
Restore defaults	Delete the saved config the game is currently using and reset everything to the defaults.

See Emulator Options for how system-wide and per-game settings fit together.