Limits

Set user defined limits by adding overrides to /etc/systemd/system.conf and /etc/systemd/user.conf

Games

Nofile may need increasing.

Create an override and set it.

For user:

nano /etc/systemd/user.conf.d/nofile.conf

[Manager]
DefaultLimitNOFILE=8192

For system:

cp /etc/systemd/user.conf.d/nofile.conf /etc/systemd/system.conf.d/nofile.conf