// Allow alice to manage example.service;
// fall back to implicit authorization otherwise.
polkit.addRule(function(action, subject) {
    if (action.id == "org.freedesktop.systemd1.manage-units" &&
        action.lookup("unit") == "example.service" &&
        subject.user == "alice") {
        return polkit.Result.YES;
    }
});

# game server commands
Cmnd_Alias GAME_CMDS = /usr/bin/systemctl start <game service>, /usr/bin/systemctl stop <game service>

unprivileged_user ALL=(ALL) NOPASSWD: GAME_CMDS