How to Play a DVD in Ubuntu
Ubuntu, by default, does not include the necessary libraries or codecs to decode DVDs. As such, it will not play commercial videos off of them. This is how to play a DVD in Ubuntu.
Install Codecs
Using the Terminal
If you are more technically experienced, you may find it significantly faster and easier to install via the terminal.
*Note: To paste in the terminal, DO NOT use Ctrl+V. Use Ctrl+Shift+V.
The same applies to copying and cutting.
You will be prompted for your password. When you provide it, no dots, stars, or other characters will appear in place of the letters. This is normal. Proceed and hit enter.
You may need to confirm you want to install certain things using tab to navigate text-buttons and space to check boxes.
Congratulations, you can now Play a DVD in Ubuntu!
Playing DVDs
VLC Media Player

Open the dashboard and launch VLC Media Player. You can find it by searching for VLC.
If VLC is not installed, you can Install VLC ›
Open VLC. If VLC does not play your DVD automatically, click File and select Open Disc.
Click Play.
Totem Media Player
Open the dashboard and launch Movie Player. You can find it by searching for Totem.
If Totem does not play your DVD automatically, click Movie and select Open. Select your DVD (in the left hand column and click Play.