I use Steam for typically-sourced games, and wine-proton for games. Below is uninteresting stuff that gives no Gentoo-specific advantages.
As per the wiki ⇗, add the repository steam-overlay and configure:
/etc/portage/package.use/steam
app-accessibility/at-spi2-core abi_x86_32
app-arch/bzip2 abi_x86_32
app-arch/lz4 abi_x86_32
app-arch/zstd abi_x86_32
dev-db/sqlite abi_x86_32
dev-lang/rust-bin abi_x86_32
dev-libs/dbus-glib abi_x86_32
dev-libs/elfutils abi_x86_32
dev-libs/expat abi_x86_32
dev-libs/fribidi abi_x86_32
dev-libs/glib abi_x86_32
dev-libs/gmp abi_x86_32
dev-libs/icu abi_x86_32
dev-libs/json-glib abi_x86_32
dev-libs/libevdev abi_x86_32
dev-libs/libffi abi_x86_32
dev-libs/libgcrypt abi_x86_32
dev-libs/libgpg-error abi_x86_32
dev-libs/libgudev abi_x86_32
dev-libs/libgusb abi_x86_32
dev-libs/libpcre2 abi_x86_32
dev-libs/libtasn1 abi_x86_32
dev-libs/libunistring abi_x86_32
dev-libs/libusb abi_x86_32
dev-libs/libxml2 abi_x86_32
dev-libs/lzo abi_x86_32
dev-libs/nettle abi_x86_32
dev-libs/nspr abi_x86_32
dev-libs/nss abi_x86_32
dev-libs/openssl abi_x86_32
dev-libs/wayland abi_x86_32
dev-util/spirv-tools abi_x86_32
dev-util/sysprof-capture abi_x86_32
gnome-base/librsvg abi_x86_32
gui-libs/libdecor abi_x86_32
llvm-core/llvm abi_x86_32
media-gfx/graphite2 abi_x86_32
media-libs/alsa-lib abi_x86_32
media-libs/flac abi_x86_32
media-libs/fontconfig abi_x86_32
media-libs/freetype abi_x86_32
media-libs/glu abi_x86_32
media-libs/harfbuzz abi_x86_32
media-libs/lcms abi_x86_32
media-libs/libepoxy abi_x86_32
media-libs/libglvnd abi_x86_32
media-libs/libjpeg-turbo abi_x86_32
media-libs/libogg abi_x86_32
media-libs/libpng abi_x86_32
media-libs/libpulse abi_x86_32
media-libs/libsdl2 abi_x86_32
media-libs/libsndfile abi_x86_32
media-libs/libva abi_x86_32
media-libs/libvorbis abi_x86_32
media-libs/mesa abi_x86_32
media-libs/openal abi_x86_32
media-libs/opus abi_x86_32
media-libs/tiff abi_x86_32
media-sound/lame abi_x86_32
media-sound/mpg123-base abi_x86_32
media-video/pipewire abi_x86_32
net-dns/c-ares abi_x86_32
net-dns/libidn2 abi_x86_32
net-libs/gnutls abi_x86_32
net-libs/libasyncns abi_x86_32
net-libs/libndp abi_x86_32
net-libs/libpsl abi_x86_32
net-libs/nghttp2 abi_x86_32
net-libs/nghttp3 abi_x86_32
net-misc/curl abi_x86_32
net-misc/networkmanager abi_x86_32
net-print/cups abi_x86_32
sys-apps/dbus abi_x86_32
sys-apps/systemd abi_x86_32
sys-apps/systemd-utils abi_x86_32
sys-apps/util-linux abi_x86_32
llvm-core/clang abi_x86_32
sys-libs/gdbm abi_x86_32
sys-libs/gpm abi_x86_32
sys-libs/libcap abi_x86_32
sys-libs/libudev-compat abi_x86_32
sys-libs/ncurses abi_x86_32
sys-libs/pam abi_x86_32
sys-libs/readline abi_x86_32
sys-libs/zlib abi_x86_32
virtual/glu abi_x86_32
virtual/libelf abi_x86_32
virtual/libiconv abi_x86_32
virtual/libintl abi_x86_32
virtual/libudev abi_x86_32
virtual/libusb abi_x86_32
virtual/opengl abi_x86_32
virtual/rust abi_x86_32
x11-libs/cairo abi_x86_32
x11-libs/extest abi_x86_32
x11-libs/gdk-pixbuf abi_x86_32
x11-libs/gtk+ abi_x86_32
x11-libs/gtk+ abi_x86_32
x11-libs/libdrm abi_x86_32
x11-libs/libICE abi_x86_32
x11-libs/libpciaccess abi_x86_32
x11-libs/libSM abi_x86_32
x11-libs/libvdpau abi_x86_32
x11-libs/libX11 abi_x86_32
x11-libs/libXau abi_x86_32
x11-libs/libxcb abi_x86_32
x11-libs/libXcomposite abi_x86_32
x11-libs/libXcursor abi_x86_32
x11-libs/libXdamage abi_x86_32
x11-libs/libXdmcp abi_x86_32
x11-libs/libXext abi_x86_32
x11-libs/libXfixes abi_x86_32
x11-libs/libXft abi_x86_32
x11-libs/libXi abi_x86_32
x11-libs/libXinerama abi_x86_32
x11-libs/libxkbcommon abi_x86_32
x11-libs/libXrandr abi_x86_32
x11-libs/libXrender abi_x86_32
x11-libs/libXScrnSaver abi_x86_32
x11-libs/libxshmfence abi_x86_32
x11-libs/libXtst abi_x86_32
x11-libs/libXxf86vm abi_x86_32
x11-libs/pango abi_x86_32
x11-libs/pixman abi_x86_32
x11-libs/xcb-util-keysyms abi_x86_32
x11-misc/colord abi_x86_32
# nvidia
gui-libs/egl-gbm abi_x86_32
gui-libs/egl-wayland abi_x86_32
gui-libs/egl-x11 abi_x86_32
x11-drivers/nvidia-drivers abi_x86_32
/etc/portage/package.accept_keywords/overlays
*/*::steam-overlay ~amd64
/etc/portage/package.accept_keywords/steam
games-util/game-device-udev-rules
sys-libs/libudev-compat
and install steam-launcher.
I use wine-proton (aka Valve's fork of Wine) because yeah.
/etc/portage/package.use/wine
# wine
x11-libs/libXcursor abi_x86_32
x11-libs/libXfixes abi_x86_32
x11-libs/libXi abi_x86_32
x11-libs/libXrandr abi_x86_32
x11-libs/libXrender abi_x86_32
x11-libs/libXxf86vm abi_x86_32
x11-libs/libXcomposite abi_x86_32
sys-apps/dbus abi_x86_32
media-libs/fontconfig abi_x86_32
media-libs/libglvnd abi_x86_32
media-libs/libsdl2 abi_x86_32
net-libs/gnutls abi_x86_32
media-libs/freetype abi_x86_32
media-libs/vulkan-loader abi_x86_32 layers
media-libs/vulkan-layers abi_x86_32
dev-util/vulkan-utility-libraries abi_x86_32
x11-libs/libX11 abi_x86_32
x11-libs/libXext abi_x86_32
media-libs/alsa-lib abi_x86_32
dev-libs/glib abi_x86_32
media-libs/gst-plugins-base abi_x86_32
media-libs/gstreamer abi_x86_32
media-libs/libpulse abi_x86_32
sys-libs/libunwind abi_x86_32
dev-libs/wayland abi_x86_32
x11-libs/libxkbcommon abi_x86_32
media-plugins/gst-plugins-meta abi_x86_32
media-libs/gst-plugins-good abi_x86_32
media-plugins/gst-plugins-pulse abi_x86_32
media-libs/gst-plugins-bad abi_x86_32
app-arch/bzip2 abi_x86_32
x11-libs/libdrm abi_x86_32
media-libs/libva abi_x86_32
x11-libs/libxcb abi_x86_32
x11-libs/libXau abi_x86_32
x11-libs/libXdmcp abi_x86_32
x11-libs/libpciaccess abi_x86_32
sys-libs/zlib abi_x86_32
dev-libs/libxml2 abi_x86_32
dev-libs/libffi abi_x86_32
media-libs/libsndfile abi_x86_32
net-libs/libasyncns abi_x86_32
media-libs/flac abi_x86_32
media-libs/libogg abi_x86_32
media-libs/libvorbis abi_x86_32
media-libs/opus abi_x86_32
media-sound/lame abi_x86_32
media-sound/mpg123-base abi_x86_32
sys-libs/libcap abi_x86_32
sys-libs/pam abi_x86_32
sys-libs/gdbm abi_x86_32
sys-libs/readline abi_x86_32
sys-libs/ncurses abi_x86_32
x11-libs/pango abi_x86_32
x11-libs/libXv abi_x86_32
media-libs/graphene abi_x86_32
media-libs/libpng abi_x86_32
media-libs/libjpeg-turbo abi_x86_32
dev-libs/fribidi abi_x86_32
media-libs/harfbuzz abi_x86_32
x11-libs/cairo abi_x86_32
x11-libs/libXft abi_x86_32
dev-libs/lzo abi_x86_32
x11-libs/pixman abi_x86_32
media-gfx/graphite2 abi_x86_32
dev-libs/icu abi_x86_32
dev-libs/libpcre2 abi_x86_32
sys-apps/util-linux abi_x86_32
dev-libs/libtasn1 abi_x86_32
dev-libs/libunistring abi_x86_32
dev-libs/nettle abi_x86_32
dev-libs/gmp abi_x86_32
net-dns/libidn2 abi_x86_32
media-video/pipewire abi_x86_32
gui-libs/libdecor abi_x86_32
media-libs/mesa abi_x86_32
dev-libs/expat abi_x86_32
dev-util/spirv-tools abi_x86_32
llvm-core/llvm abi_x86_32
x11-libs/libxshmfence abi_x86_32
x11-libs/xcb-util-keysyms abi_x86_32
app-arch/zstd abi_x86_32
x11-libs/gtk+ abi_x86_32
app-accessibility/at-spi2-core abi_x86_32
media-libs/libepoxy abi_x86_32
x11-libs/gdk-pixbuf abi_x86_32
x11-libs/libXdamage abi_x86_32
gnome-base/librsvg abi_x86_32
x11-libs/libXtst abi_x86_32
virtual/libintl abi_x86_32
virtual/libudev abi_x86_32
sys-apps/systemd-utils abi_x86_32
dev-lang/rust-bin abi_x86_32
virtual/libiconv abi_x86_32
virtual/opengl abi_x86_32
virtual/glu abi_x86_32
media-libs/glu abi_x86_32
# wine-proton
dev-libs/libgcrypt abi_x86_32
dev-libs/libgpg-error abi_x86_32
media-plugins/gst-plugins-libav abi_x86_32
media-video/ffmpeg abi_x86_32
virtual/zlib abi_x86_32
# wine-proton gstreamer, etc.
media-libs/libbs2b abi_x86_32
media-libs/dav1d abi_x86_32
media-sound/gsm abi_x86_32
media-libs/libiec61883 abi_x86_32
sys-libs/libavc1394 abi_x86_32
sys-libs/libraw1394 abi_x86_32
media-libs/libjxl abi_x86_32
media-libs/libaom abi_x86_32
media-libs/libass abi_x86_32
media-libs/libplacebo abi_x86_32
media-libs/libmodplug abi_x86_32
media-libs/rubberband abi_x86_32
app-arch/snappy abi_x86_32
media-libs/speex abi_x86_32
net-libs/srt abi_x86_32
net-libs/libssh abi_x86_32
media-libs/svt-av1 abi_x86_32
media-libs/libtheora abi_x86_32
media-libs/libv4l abi_x86_32
media-libs/libwebp abi_x86_32
media-libs/x264 abi_x86_32
media-libs/x265 abi_x86_32
media-libs/xvid abi_x86_32
media-libs/zimg abi_x86_32
media-libs/libsamplerate abi_x86_32
sci-libs/fftw abi_x86_32
media-libs/shaderc abi_x86_32
dev-libs/xxhash abi_x86_32
dev-util/glslang abi_x86_32
app-arch/brotli abi_x86_32
dev-cpp/highway abi_x86_32
virtual/opencl abi_x86_32
dev-libs/opencl-icd-loader abi_x86_32
Also see /var/db/repos/gentoo/app-emulation/wine-proton/files/README.gentoo to set the following defaults in your zshrc:
export WINEFSYNC=1 # requires linux kernel >=5.16
export WINE_LARGE_ADDRESS_AWARE=1 # helps 32bit memory
# WINEPREFIX=/path/to setup_dxvk.sh install --symlink # requires app-emulation/dxvk
# WINEPREFIX=/path/to setup_vkd3d_proton.sh install --symlink # requires app-emulation/vkd3d-proton
using waydroid
/etc/portage/package.use/android
sys-libs/libcap static-libs
In the kernel I also hit split lock for some stuff.
https://www.phoronix.com/news/Linux-Splitlock-Hurts-Gaming
/etc/dracut.conf
kernel_cmdline+=" split_lock_detect=off "
/etc/portage/package.accept_keywords/gaming
gui-wm/gamescope ~amd64
media-libs/vkroots ~amd64