The legal pages are just standard pages that have a custom navigation bar and use shortcodes to insert data from the theme.
To add a new legal page:
- Add a new page.
- Under the Page Attributes section, set the Template to Legal Page.
- Under the Page Attributes section, set the Parent Page to Legal.
- Go to Appearance > Menus > Legal Menu and add the new page.

This will add the 'legal' base to the permalink and also display a submenu at the top of the page.