For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:Factory:git-workflow:staging:dirkmueller:gamescope:13/openSUSE_Tumbleweed/devel:Factory:git-workflow:staging:dirkmueller:gamescope:13.repo
zypper refresh
zypper install gamescope
For openSUSE Slowroll run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:Factory:git-workflow:staging:dirkmueller:gamescope:13/openSUSE_Slowroll/devel:Factory:git-workflow:staging:dirkmueller:gamescope:13.repo
zypper refresh
zypper install gamescope
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:Factory:git-workflow:staging:dirkmueller:gamescope:13/16.0/devel:Factory:git-workflow:staging:dirkmueller:gamescope:13.repo
zypper refresh
zypper install gamescope