The Caligula: Whenever he takes over the world or becomes CEO of Dilbert's company, his guiding leadership principle is For the Evulz.
Characterization Marches On: He was originally explicitly Dilbert's pet, complete with walks, attempts at getting him to fetch things, and games of Frisbee. Today, he is officially referred to as Dilbert's "roommate" and Adams remarks that he can't imagine trying to write Dogbert as a pet now.
Dumbass Has a Point: He's only an idiot when managing his subordinates. When dealing with other departments and upper management he's actually the straight man undermined by Dilbert's social ineptitude and bluntness.
Mean Boss: Mostly in earlier strips and the TV series. Adams says that in the strip, PHB has become "more noncaring than overtly mean".
Ascended Extra: Wally - or at least, his physical appearance - originally started out as a model for generic employees (akin to Ted, or perhaps Barney Calhoun), and several of Dilbert's co-workers in the early years of the strip bore his appearance. Slowly, however, the individual character emerged, eventually giving form to Wally.
Brilliant, but Lazy: His schemes to get out of doing work are sometimes convoluted enough to qualify him for Magnificent Bastard consideration... he's obviously a very intelligent guy, just not very motivated.
Reality Subtext: Adams stated that he once worked with an extremely intelligent man at Pac Bell, who discovered he'd earn more money from severence than actually working there thanks to a generous employee buy-out programŚfor the company's worst employees. He stated he was absolutely fascinated by "one of the more brilliant people I've met" working hard at being incompetent, rude, and generally poor at his job to qualify for the buy-out program.
Psychic Powers: In the Noughties a Running Gag developed that his time at the Indian Institute of Technology had left him with telekinesis and the ability to make people's heads explode by thinking about it.
Dogbert: "The supreme court of India recently voted to uphold a law making it a crime to be born gay. To commemorate that hopelessly ignorant decision, Asok the Intern is now officially gay. Okay, we're done here."
Asok: "Good, because I have a lot of gay stuff to do."
Token Minority: Adams has said Asok was an attempt at an aversion - he worried that adding any ethnic minority character would provoke backlash because all his characters have amusing flaws and people might regard those flaws as being a stereotype - so Asok's flaw was 'inexperience', which was obviously temporary. Naturally, due to Fan Dumb, he was still blasted as a negative stereotype to start with.
Cute Is Evil: His cuteness is actually one of the reasons he was hired.
Fan Nickname: The character had no name when he first appeared, but letters poured in asking for more Catbert. Scott Adams later said, "If hundreds of people spontaneously give a character the same name, it's a keeper."
Not so much a Sassy Secretary as a Bitter Secretary Who Hates The World, Everyone In It And The PHB In Particular. Constantly messes with the PHB, sometimes plotting to kill him, while doing her job in the most haphazard way possible.
Composite Character: They also borrowed from fellow minor character appearing in a few strips, Nervous Ted — the TV version spends a lot of time shouting about trivial and frequently downright bizarre worries.
Straw Feminist: Although not the stereotypical man-hater type. Instead, Tina is an illogical hypocrite who uses sexism as a scapegoat. Although this was her original defining character trait, it has since mostly fallen by the wayside.
Adams then made "Antina" (anti-Tina) as a response to people who thought Tina was a swipe at feminism. Antina was everything Tina was not - which immediately drew complaints that Antina was a swipe at Butch Lesbians. It's interesting to note that Antina was one of the very, very few times Dilbert's tie drooped downward.
A guy with a tall bald head who makes the PHB seem like a kind person in comparison. There have been several different CEOs in the series with the same appearance and personality, making him an upper-management version of Ted.
Unexplained Recovery: He once misunderstood Dogbert's advice to take a poison pill and consumed a literal poison pill, killing himself. He showed up again good as new with no explanation a long time later.
Sorting Algorithm of Stupidity: The Pointy Haired Boss claimed that a good manager will always hire people smarter than them and Dilbert pointed out that that must mean the CEO is the dumbest person in the company.
The Artifact: He generally had more to do before office humor took over.
Ascended Fanon: Fans used to ask if Phil and the PHB were related because they looked similar. Adams liked the idea and made them brothers.
Cool and Unusual Punishment: Has done this to people many times. One of his crueller punishments to people at Dilbert's company is to do nothing whatsoever.
Executive Meddling: Adams wanted to add the Devil to the cast as an annoying character, but his editors vetoed that idea, so he came up with Phil. Adams would later admit that Phil is a much funnier concept than what he originally had in mind.
Gosh Dang It to Heck!: "I Darn you to Heck." This is, indeed, distinct from hell in more than just name; while hell is, well, hellish, heck is mildly unpleasant, such as being forced to sit in a mostly empty room with no magazine and a temperature slightly above comfortable.
Will They or Won't They?: In August '94 Adams started a reader poll asking whether Dilbert should go all the way with Liz or not. Female fans were practically unanimous in their voting that Dilbert should do the deed, but male fans were split. Half said he should, while half reported they used Dilbert's luck in relationships as a measurement for their own nerdiness, and they thought "Dilbert shouldn't get lucky before I do." Surprised by the polarized reaction, Adams decided on an ambiguous answer. This strip resulted. The 'down' tie was meant to be a code that Dilbert and Liz had sex, but the way it's presented is that any fan can draw the conclusion they prefer.