This is notably one of the few live-action TV adaptations that's allowed to outright use Batman complete with onscreen appearances, whereas DC normally enforces an embargo to prevent audiences from being "confused" by the different continuities (apparently they don't think audiences are smart enough to know what an alternate continuity is)note this had the side effect of Green Arrow being used in his place, most notably seen in Smallville; ironically, for a while, Green Arrow himself was seen as a poor man's substitute for Batman. The fact that it's separate from the Arrowverse and is airing on DC's private streaming service may have something to do with it. However, he was mostly The Ghost in season 1, played by stunt actors in a hallucation in the season 1 finale, whereas in season 2, he does physically appear, but only as Bruce Wayne.
Titans marks the live-action debut of long-serving and iconic Titan Donna Troy, who had many legal issues in the past preventing her from appearing outside of comic books for the longest time (hence she only had extremely brief cameos in the 2003 animated series).
Approval of God: Marv Wolfman and George Perez have both been supportive of the series.
Many actors are of a lesser-known variety as opposed to well-known stars. The best known of the actors announced so far are probably Brenton Thwaites, Ryan Potter, Alan Ritchson, Minka Kelly, and Conor Leslie. Many other actors don't even have their Wikipedia pages yet. Australian child actress Teagan Croft as Raven is especially notable, as this is her first major role outside her homeland, only having two previous TV roles and a film back home, plus a theater role in To Kill a Mockingbird.
Garfield Logan is supposedly a teenager, but is played by twenty three-year-old Ryan Potter in his introduction. This was presumably done because of the character's frequent nude scenes, which would have been harder to film with an underage actor.
Alan Ritchson and Minka Kelly also play Hank Hall and Dawn Granger during their college years while both are in their 30s.
Once the trailer for episode 11 was released, a lot of fans predicted that many of the events would be Trigon giving Dick hallucinations.
In Japan, some fans predicted either Yuuki Kaji or anyone else from the Japanese voice cast from Attack on Titan would end working in the dub of this series due to the sole name of the show. Not only they got it right on the former, he also managed to voice Robin, the leader of the titular team.note Albeit he already voiced Robin before in Batman Ninja.
Lying Creator: Brenton Thwaites raised a lot of fans' hackles when he said that Dick split from Batman because Batman became a killer, yet nothing in the show outright confirms this and when Batman finally appears, Dick is shocked that he violates his one "no-kill" rule against both criminals and cops. Even then, this is all inside Dick's head courtesy of Trigon. Though to be fair, given all the changes the show has gone through behind the scenes, Thwaites' comment may be less a "lie" and more of a What Could Have Been.
A very weird example wherein two separate actors have simultaneously been cast for the same part. Bruno Bichir was cast as Niles Caulder/The Chief for the episode that introduces his team, while Timothy Dalton is portraying him on his own show.
For many reasons, including the change of genre from animation to live-action, most foreign dubs has also changed the voice actors from previous incarnations:
The Latin American Spanish one is a very brutal one, as the dub were switched out from Venezuela (animated series) to Mexico (live-action).
The Japanese one is also pretty notorious on this, as it also replaced all the long-time voice actors from the Teen Titans's era, considering they also dubbed them in both Teen Titans Go!, Young Justice and most Japanese dubs of the DCAU. The only exception is Yuuki Kaji as Robin, as he already voiced him before in Batman Ninja, although as the Damian Wayne iteration of Robin instead of Dick Grayson.
Role Reprise: A very interesting cross-continuity one happens in the Latin American Spanish dub: Bruce Wayne is voiced by Sergio Gutierrez Coto, who already voiced him in the dubs of The Dark Knight Trilogy films, through only in the first season, since Gerardo Reyero voices him in the second one.
As mentioned above, the Brazilian dub reprises the voices of the main team, except for Raven.
Gar and Kory got the same voices from Teen Titans: Charles Emmanuel and Luisa Palomanes, respctively. It works well because they use their natural voices here, while, in the cartoon, they raised the pitch.
Dick was voiced by Sergio Cantú, the voice actor of his Nightwing version in the second season of Young Justice.
Ricardo Schnetzer had not only voiced Slade in the Teen Titans cartoon, but he had also voiced previous live-action versions of Slade as well, in Arrow and in The Stinger of the movie Justice League (2017).
Speaking of which, Jorge Lucas, who had voiced Batman in the DC Extended Universe, voices Bruce Wayne here.
Spoiled by the Cast List: A variation. Many of the characters appearing in the show (such as Arsenal, Donna Troy, Elasti-Girl, the Jason Todd Robin, Solstice and even Batman) have been spoiled by casting breakdowns that, while they've tried to be vague on who they are, were pretty obvious to anyone familiar with the comics.
Trailers Always Spoil: The trailer for the season 2 finale made it clear that Donna was going to be the Titan who fell. The biggest giveaway was the shot of the casket, which had her lasso next to it, and further indications were seen with the hearse being at an airport where her body would be flown to Themyscira, Dawn kneeling in front of where her costume is stored, and Donna not being present with the other heroes in the funeral shot at the end.
Barbara Gordon was going to be part of the team when it was in development for TNT, as her pre-New 52 identity Oracle. That being said, her existence is confirmed during the Season 1 finale.
The first season was intended to be 12 episodes long, but was reduced to 11 episodes when the creative team repurposed the planned finale as Season 2's opening episode; this also lead to Season 1's finale being an outright Downer Ending until the second season resolves the Cliffhanger.
Gar was supposed to be killed by a possessed Dick drowning him in a bathtub and Rachel would resurrect him. This scene would have involved him transforming into an eel as a cost effective alternative to the octopus the writers wanted.
The Doom Patrol from the Spin-Off series would have appeared. They would arrive courtesy of Negative Man's powers, establishing The Multiverse and showcasing the team there as from a different universe rather than the iteration seen earlier in the series. They would have also joined the battle against Trigon. Because this was cut, Crisis on Infinite Earths (2019) winds up being how Titans and Doom Patrol are established as separate instead.
Rachel would have gone through a portal to Azarath to train for 300 days. She would have returned with new abilities, such as flight and energy blasts, and would have defeated Trigon by absorbing him into her soul-self.
Trigon was supposed to be much larger, closer to his size in the comics.
Dick would have suited up as Nightwing, with the costume heavily obscured through various camera methods with no plans to have the entire costume shown.
Kory and Donna would have worn their hero costumes.
The writers wanted to introduce Cyborg but no actor had been cast by that point and time constraints prevented his inclusion, so the writers settled for mentioning him only.
Donna would have mentioned Wally West.
After the battle with Trigon the team was supposed to fight unknown henchmen that were implied to be working for H.I.V.E.
Some leaked photos show that Rachel was supposed to receive her hero costume. Kory is also seen in a new costume, one that is different from either her civilian or hero costumes and also has an unknown book on hand in one of the photos. Rachel and Kory are also seen in an unknown building with light shining in and seem to be training. This all seems to imply that Kory would have joined Rachel for her time in Azarath.
Crisis on Infinite Earths (2019) uses footage of Hawk and Jason from the original finale due to the cast's unwillingness to film new footage for the event, repurposed to show the two instead seeing the red sky of their Earth being destroyed.
The writers didn't plan to use Deathstroke as the main villain of Season 2 at first. They instead planned for it to be H.I.V.E.
Word of God confirmed Deathstroke survived the events of season 2, but that the scene actually showing him waking up from his defeat was cut from the finale to avoid confusing people into thinking he would directly return in season 3 (and to avoid it distracting from Blackfire's new Big Bad status in that season).