If you think you can play dvd on plain Debian just by inserting dvd in the tray, you are wrong. But fortunately we can install needed library easily. I did the steps described on this page.

1. Add these two line into “/etc/apt/source.list”.

deb http://download.videolan.org/pub/debian/stable/ /
deb-src http://download.videolan.org/pub/debian/stable/ /

2. Add apt-key for this repository by doing this:

wget -O - http://download.videolan.org/pub/debian/videolan-apt.asc|sudo apt-key add -

3. Update the apt.

sudo apt-get update

4. Install libdvdcss2.

sudo apt-get install libdvdcss2

5. That’s it! Now you can play dvd with your favorite video player.