Black Guard

Allies: Clu, Jarvis, Rinzler
Enemies: Defined by Clu, their master

An extremely elite corps inside the Grid that ensure all programs follow Clu's directives. His personal guard.

Castor

Actor: Michael Sheen
Allies: Gem

Castor is a vivacious and well-known program in the Grid who runs the End of Line Club at the top of the tower in Tron city.

Clu

Actor: Jeff Bridges
User: Kevin Flynn
Allies: Jarvis, Rinzler, Black Guard, Sentries
Enemies: Programs defying system rules

Clu was originally a search program created by Kevin Flynn to explore inside the ENCOM mainframe for proof he created ENCOM's most-popular games. Clu was found and destroyed by the Master Control Program. Flynn created another program named CLU after returning from the Grid with a more specific task in mind...

Gem

Actress: Beau Garrett
Allies: Castor, Sirens

Gem belongs to a group of programs known as Sirens. Her function, as with all Sirens, is to prepare programs for the games by providing fitted armor — and in Sam Flynn's case — an identity disc.