freeciv software package provides Civilization turn based strategy game, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install freeciv
freeciv is installed in your system.
Make ensure the freeciv package were installed using the commands given below,
$ sudo dpkg-query -l | grep freeciv *
You will get with freeciv package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Games |
| Package | freeciv |
| Version | 2.5.5-1 |
| Description | Civilization turn based strategy game |
| Sub Section | Games |