For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:liguros/openSUSE_Tumbleweed/home:liguros.repo
zypper refresh
zypper install 0ad
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:liguros/15.6/home:liguros.repo
zypper refresh
zypper install 0ad
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:liguros/15.5/home:liguros.repo
zypper refresh
zypper install 0ad
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:liguros/15.4/home:liguros.repo
zypper refresh
zypper install 0ad