It would be wise to have watched the whole first season of Code Geass before watching these Specials.
"Code Geass: Hangyaku no Lelouch Picture Drama" are a great addition to the back story of some of these characters of Code Geass.
If anything, they are entertaining enough to watch.
Episode 1 is How Lelouch and Susaku met at a young age.
Episode 2 was Milly, Nina, Shirley, and Kallen talking in the Ashford Academy Onsen/bathing house. It's quite sexy.
Episode 3, Jeremiah confides to Villetta about how he failed to protect Marianne 8 years ago.
Episode 4, Rivalz is talking to Susaku about how Lelouch is quiet about his childhood while
repairing a bike. Susaku talks to Cecile and Lloyed afterwards, they make Susaku feel more at home.
Episode 5 was a comedic episode of the Student Counsel going to the beach. Euphemia and Cornelia have an announcement.
Episode 6 the student council have a cosplay party!
Episode 7 Lelouch has trouble explaining to Nunally why CC is at their house, and Sayoko has a surprise when she gets home.
Episode 8 Nunnally remembers how kind and gentle Eyphemia was as a child.
Episode 9 Was a serious episode about the departure of Susaku and Lelouch's childhood.
The animation is what you would expect of a Picture drama.
The art is quite unique, most of the art in each episode was made with a rough draft style, (I actually like the look a lot), but some are higher quality drawings of what you would expect (Especially episode 2... I'm not complaining.)
The usual soundtrack from the show.
The Seiyuu are excellent.
I've always liked these types of specials, that include OVA specials.
The fact that each of these specials adds some background to the characters, and brings some light humor is enough for it to be worth watching.
If you've purchased the DVDs of Code Geass, you will not be disappointed.