- Acting for Two:
- Actor-Inspired Element: Kevin wears a choker because Greg Cipes does too.
- Cash Cow Franchise: Ben 10 is one of Cartoon Network's most popular multiseries, so natch.
- Dawson Casting: The casting for the live-action movie is fine, until the actor playing Ben is revealed to be a 23-year old. Still, the last Ben wasn't 10, so...
- Fandom Nod: When Ben explains the current Sumo Slammers series to Kevin in the final episode, he has a few very... familiar-sounding complaints:This isn't the best one to start with. It's not Sumo Slammers classic. It's Sumo Slammers: Hero Generation. [...] It's a sequel to the original show, but they kinda messed it up. It's like five years later and the bad guy Kanko has teamed up with the hero Ishiyama. It's not very realistic, is all I'm saying.
- Flip-Flop of God: Not so much flip-flopping as one Word of God can override another Word of God. Dwayne McDuffie takes the heat for when this happens.
- Inspiration for the Work: Dwayne McDuffie got the idea for the Highbreed from, of all things, bananas. Ben even references this by calling the Highbreed Supreme "the Highbreed top banana."
- Playing Against Type: Jeff Bennett as Azmuth and Ghostfreak.
- Off-Model: Multiple episodes show Ben using parts of the Omnitrix other than the dial to select aliens, including twisting the switches on the side in X = Ben + 2 and twisting the base of the Omnitrix in a third season episode.
- The Other Darrin:
- Ben, Gwen, and Kevin, go from Tara Strong, Megan Smith, and Charlie Schlatter to Yuri Lowenthal, Ashley Johnson, and Greg Cipes. It's Justified by the Time Skip.
- Fred Tatasciore was replaced as Cannonbolt and Way Big and Dave Wittenberg as Upchuck, both by Dee Bradley Baker when Ben transformed into them in the second season finale.
- Steve Blum was also replaced as Vilgax due to schedule conflicts, the role being given to James Remar, who himself didn't voice the character in Vilgax Attacks!, one of the video games, where he was instead played by John Dimaggio, whose rendition of Vilgax is much closer than James Remar's. Steve finally reprised the role in Omniverse.
- When Vilgax and Azmuth use the Omnitrix in the episode "Primus," their transformed states use the same voices, rather than the usual guy.
- During their appearance in the original series, Ben's parents, Carl and Sandra, were voiced respectively voiced by series regulars Dee Bradley Baker (Stinkfly, Eye Guy, Wildmutt) and Tara Strong (Ben, Ben as Upgrade). In Alien Force, they're replaced respectively by Don McManus and Beth Littleford, who played the roles in Race Against Time.
- Post-Script Season: Across its first two seasons, the show tells a sprawling epic storyline of a battle against one of the oldest races in creation, culminating in a final episode in which virtually every single dangling plot thread, character and story concept the series has set up is convincingly brought together for a dramatic final battle that ended with the saving of the entire universe... aaaand then they made a third season. The season distinguished itself by bringing back the Big Bad from the original series, but ultimately achieved little other than setting up the next incarnation of the series with its finale, consisting almost entirely as it did of one-shot adventures of no consequence, with little to no use of the new ideas and concepts set up in the season premiere. The third season was quite clearly not originally planned for the final moment of season two, in which Ben looks at the Omnitrix and claims to have a new set of ten aliens he does not recognize: quite obviously intended as an open ending that was then ignored when season three began and he had his standard ten still in place.
- Real-Life Relative: For her elderly disguise (seen only in "What Are Little Girls Made Of?"), Verdona is voiced by Barbara Bain. In her true Anodite form and the flashback to Verdona's first meeting with Max in "Moonstuck," her daughter Juliet Landau assumes the role. As such, Landau could be thought of as a younger representation of her mother (or Bain could be thought of as an older representation of her daughter. Or both).
- Relationship Voice Actor:
- Greg Cipes and Ashley Johnson voicing characters with a mutual attraction to each other? Teen Titans, anyone? Either that, or Super Robot Monkey Team Hyperforce Go!.
- Speaking of Teen Titans, all of the Titans except for Starfire have been brought into this series. Kevin is Beast Boy, Gwen is Terra, Young Ben / Attea is Raven, Manny Armstrong / Hex is Cyborg, JT / Jimmy Jones is Robin, the Omnitrix aliens are Silkie, Darkstar is Aqualad. Teenage Ben himself would go on to appear in Teen Titans: Trouble in Tokyo.
- Talking to Himself: Every single alien in the Omnitrix is voiced by Dee Bradley Baker, except for Alien X, Ghostfreak, and Rath.
- What Could Have Been:
- Man of Action's idea for the sequel series was Ben 10: Hero Generation, in which a teenage Ben and Gwen would become mentors to a group of kids with mysterious alien powers. However, Cartoon Network gave the sequel project over to Glen Murikami and Dwayne McDuffie, and Ben 10: Alien Force was developed instead. While some remnants of Man of Action's concept can be found with the "Plumber's Helpers" characters, they take a backseat to the action and are not mentored by Ben and Gwen, who instead fight evil alongside a reformed Kevin instead.
- One of the writers said that there was a big story planned for season three that involved Kevin absorbing more energy (presumably to save Gwen) and fighting against the insanity that comes with it but ultimately becoming evil. Cartoon Network approved it at first but then they chickened out at the last minute, so the writers had to scrap that story and start a new arc for the season from scratch. This same story was rescued for the first season of Ultimate Alien but with a different approach, in particular with a happy ending.
- Word of God: One of the main writers, Dwayne McDuffie, has a thread where he answers questions and brings foreshadowing to the series. Anyone who is majorly confused with the continuity errors in this show should check this out). It addresses many oddities and seeming plot holes.
- Sixsix and Sevenseven's language is too complex for translators to handle.
Trivia / Ben 10: Alien Force