"Yoda-like mentor" for the protagonists realized March 2013 (p. 40)
Rey
Originally known as Kira (first directly stated page 20)
First realized in January 2013, during the concept art stage (p. 20)
Early Kira a "loner, hothead, gear-head, badass" --screenwriter Michael Arndt
April 17 story and design meeting between Michael Arndt, Rick Carter, and J.J. Abrams at Bad Robot Productions turns Kira into a junk planet scavenger, "initially works in a used car lot of sorts for an elder fatherly figure, a Republic pilot", Kira watches ships and daydreams of leaving backwater planet (p 54)
Finn
Originally known as Sam (p. 20)
Original Sam "pure charisma" --screenwriter Michael Arndt
First realized in January 2013, during the concept art stage (p. 20)
April 17 meeting turns Sam into beginning as a stormtrooper (p. 54)
Poe Dameron
Originally "John Doe" as a temporary name (p. 40)
Was almost a Jedi, then a bounty hunter (p. 49)
April 17 meeting turns Doe into "Republic military man" with droid carrying important info ("consciously reflecting R2-D2"), must team up with Sam to complete mission. (p. 54)
Kylo Ren
Originally known as "Jedi Killer", name given around March 2013 but at this point has no origin (p. 40)
March '13 explores an attack on outpost by Jedi Killer and his "hooligans" -- initially conceived as "pirate-mercenaries" before later becoming stormtroopers -- and the realization of the climatic showdown on an ice planet (p. 40)
March '13, J.J. sees concept art of Jedi Killer looking like Vader, springboads the Vader "impostor" idea to "mess with Luke's head" (p. 40)
At one point considered Jedi Killer owning his own droid, possibly a torture droid (p. 120)
"The Jedi Killer design was like trying to land a helicopter on a penny. We couldn't be too Vader-ish, but we couldn't reference something else too heavily, either." --Dillon (p. 131)
Maz Kanata
"Archetypal mentor character" of Maz Kanata first "tackled" June '13 (p. 78)
