Absurdly Sharp Blade: The Warden swords' in-novel ability to cut through anything is represented as an option to make it hit for Weapon:6 damage. For comparison's sake, the swords are normally Weapon:3, and Weapon:4 damage and above is usually reserved for powerful spells and/or battlefield explosives.
After the End: The section mentioned below about possibly killing off Harry in the background points out that there are certain events in the setting that could only have been stopped by Harry, several of which would pretty much spell the end of the world in some fashion. It advises you to keep this in mind if that's the route you take.
Alternate Continuity: By Word of God, the RPG rulebooks were written in a slightly different version of Dresden's world—for one, Billy, as the writer, knows about things that Book!Harry would never, ever have told anyone, at least at the point in the storyline where the rulebooks were written. Most of this information comes with a margin note by Harry along the lines of, "You can't put this in, Billy, or [whoever it is] is gonna be pissed."
Alt Text: Harry uses the margin for a page in the RPG to work out a runic formula. Copy the runes and paste them into an alphabetical font, and it translates to "You re very clever." A second note from Bob adds, "You forgot [the rune for a]!"
Anti-Frustration Features: Among other things, it suggests that you don't bother rolling unless the failure of a roll will be interesting. Also, if a player spends more than one fate point on a successful attack, only to find out that the target has Physical Immunity to it, the rules state that the player gets back all but one fate point so they don't go to waste.
Badass Normal: The game helps balance things for non-supernaturals by giving them extra fate points, and thus extra influence on the outcome of the story. While a pure mortal might not be able to fling fireballs from their fingertips or take punches from a troll, they end up with enough fate points to nudge the dice in their favor at crucial moments.
Bad Powers, Bad People: The list of supernatural powers says that while the list is all in one spot for convenience's sake, some powers are really only going to be found on monsters and villains unless the GM gives the okay because they're inherently destructive, such as drinking blood, eating emotions, or otherwise involve harming things and people.
Billy: [On Mimic Abilities] Itís a bit of an "evil people eater" power, so it should be treated very strictly when in PC hands.
Back Stab: Using Stealth to set up a successful ambush makes it so the victims are flat-footed, and roll their defenses from 0 instead of whatever the stat actually is. This is a lethal prospect, especially for those characters whose blocking or dodging stat is normally 4 or 5, or higher via powers, since it means the best possible roll is, at best, an 'average' result for them.
Bilingual Bonus: The illustration of Eldest Gruff (page 46 of Our World) shows Norse runes carved into his staff. Substituting in the phonetically equivalent letters in the Latin alphabet gives the message "DONUTS ARE TASTY."
Breath Weapon: One of the available powers, though the description is deliberately broad enough to include any self-generated projectile, such as the flaming poo used by the Shen demons.
California Doubling/Stargate City: Referenced in the city creation section, where Billy suggests simply making up the layout of the city, or basing it on a city you may be more familiar with. He mentions that some shows set in Chicago have used Vancouver in this method, while Harry thinks that wouldn't work.
Harry's right, actually. That series was filmed in Toronto, not Vancouver.
Canis Latinicus: The main series' use is laborated on here. In order to cast a spell, the caster has to form a "construct" around it. Basically a psychic container to shape and direct the energy in use, the words of a spell are a key element of any construct. Another reason for using a language they're not really familiar with is that using your first language for your constructs can carry over into every day speech. For example, if Harry used "fire" instead of "fuego" he'd run the risk of conjuring a ball of flame anytime he happened to be talking about fire (and then the burning building really would be his fault).
Cassandra Truth: The power "Cassandra's Tears" allows a character to receive visions of the future, but with the stipulation that nobody will believe them. Hilariously, in the "Who's Who" section, the margin comments by Harry and Billy on one character with this power consists mostly of them disbelieving that she in fact had it.
Cast from Hit Points: The magic system sort of does this. You take a hit to your mental stress track any time you cast a spell, and depending on how the dice roll, you might take physical stress or even consequences to make sure it goes off right.
The City: A central part of game planning is creating the game's city, usually including several aspects, locations, and "faces" for the player characters to interact with. The gamebooks include write-ups on Chicago, where the main series takes place, and Baltimore.
Combat Clairvoyance: The custom power "A Few Seconds Ahead" that canon character Abby has allows for this; she can see a few seconds into the future, allowing her to use her Lore skill to dodge attacks rather than her lower Athletics score.
Conditional Powers: Items of Power (such as the Swords of the Cross) and Sponsored Magic typically either have to be used in accordance with the sponsor's agenda, or stop working if you try to use them for ends or reasons directly opposed to that agenda—and in both cases, is usually worth a fate point.
Continuity Nod: The margin comments are mostly this, partly Foreshadowing, and partly Funny Aneurysm Moments, as it's set just after Small Favor, and thus before Turn Coat and Changes, in which tragic and permanent events changed the status quo.
Contrived Coincidence: The FATE system lets players pull these by spending fate points, for example having a lighter just when you need it, despite never smoking, or just happening to show up in the nick of time. One of the Faith powers, Guide My Hand, lets the character with the power do the "show up just when they're needed" one without spending the fate point.
Death Fic: invokedOne section of the book considers that Harry might be a Story Breaker Power, and suggests killing him off in the background. Harry is less than amused at this section.
Development Hell: The Dresden Files tabletop RPG had been in production for years, but was finally released in June 2010.
Do Not Attempt: A disclaimer of this sort appears after the description of the Shadowman's heart-explodingspell; Will specifically dismisses responsibility for getting "your fool head lopped off by a Warden" because you tried it yourself.
Dramatic Irony: Many of the margin comments contain this, given the rulebooks take place mid-way through the series, so the readers know things Dresden does not.
Enemy Civil War: Sort of alluded to. When discussing the purpose of the game in the margin comments, Dresden points out that there's rumor that Dracula was written at the behest of the White Court of vampires as an attack against the Black Court, and concludes that while no monster is going to publish a list of its own weaknesses, it just might publish a list of someone else's.
Epic Fail: Being a dice-based game, the text includes examples of what happens when you totally blow a roll, and one example is of Harry Dresden blowing a spell roll and setting something on fire. Naturally, Harry voices a complaint about this in the margins, wondering why Billy can't use the Baltimore example-game's character for those examples.
The Lawbreaker powers push toward this. By breaking one of the Laws of Magic it becomes easier to break the law again—so if you've broken the first law once, you get a +1 to later rolls if you're trying to kill, up to a max of +3. This is to represent the seductive, corrupting nature of breaking the laws of magic.
One of the game's writers was asked why some villains listed in the books didn't have their math work out—they had higher skills and different powers than their template, or the stacking system, ought to allow. The writer's answer was along the lines of, "Well, the bad guys cheat."
The irony is that one of the villains has his math work out against him, missing something like 1.5 Refinements worth of advancements.
Similarly, Sponsored Magic works sort of like a credit card—if you can't make the roll, you can get a free bonus up front, at the cost of "debt" to your sponsor in the form of compels later on that you don't get Fate Points for. The rulebook mentions that Demons and the like are always willing to "help". Of course, God is also listed as a possible sponsor, and the text notes that He's probably got a more "gentle" agenda than, say, demons and Fallen Angels.
Facepalm: One picture has Murphy doing one, with Harry commenting beneath the picture, "I make her do this way too much."
Famous Last Words: Because of the game's mechanics, while the winner of a physical confrontation decides what happens, the loser decides exactly how. This means in mortal combat, the loser almost always gets the opportunity to give some last words. And in the case of wizards, this includes Death Curses.
Fanservice: A lot of the illustrations include scantily clad women. Harry complains at one point, and Billy responds that he asked the illustrator to pick out and draw "dynamic" scenes from the case files and, well, Harry has a tendency to run into and be attacked by scantily clad women in the books.
Fix Fic: invokedIn the Our World book's listing of characters from the case files, one such character was, in Proven Guilty, mind raped to the point where Harry declared that she'd never recover. Billy writes that a player could decide to have her recover anyway, and make that the basis for a character. Harry is torn between whether he should be angry that Billy is providing false hope, or happy that Billy is providing hope at all.
Foreshadowing: Butcher sneaks this in, too. During the "Who's Who" section, it mentions the Carpenter kids and notes that a player might find inspiration in playing one of Molly's younger siblings, like Daniel, the oldest of her younger brothers. Now, guess who's stepped up to the plate in Ghost Story?
In "Your Story"'s section about world-building, Billy is talking about significant landmarks in a game and says "Maybe the Pyramids at Giza are nowhere near as bad as Chichen Itza", the latter part blacked out by Harry who says "You can't reveal that sort of thing here". This of course foreshadows Changes, which Jim was still writing when the RPG came out, where Harry and co. go to Chichen Itza and fight and destroy practically the entire Red Court, thanks to Susan's sacrifice.
Handwave: Occasionally, the book finds itself at a loss for an in-universe explanation for why a certain rule works out the way it does, and has to resort to this. In particular, in regard to using a magic specialization to improve Focus Items, it says you can't and ends somewhat helplessly with something along the lines of, "Look, it just doesn't work that way, alright?"
Healing Factor: Puts it at three levels, the highest of which allows a creature to heal from something that would normally take months or years within minutes.
Healing Hands/Intimate Healing: One example thaumaturgic spell amounts to a massage that lessens injuries. The description notes that depending on circumstances the massage could be pleasurable or even sensual.
Hero of Another Story: While many of the examples come from Harry and his pals, quite a few involve a Baltimore-based group of characters unrelated to Dresden's adventures, and the "Our World" source book contains details on those characters and their setting for players who might want to use them.
Kryptonite Factor: You aren't allowed to take any of the Toughness abilities without taking some kind of weakness. Fortunately, the weakness can provide a discount for taking the Toughness ability in question. How much of a discount depends on the weakness's availability and how well-known it is. A well known, widely available weakness, such as Iron to Faeries, will grant a big discount, while a weakness that only a small handful of people might know, such as Judas's noose to Nicodemus, may not grant any discount at all.
Kryptonite factor also works in inverse, for people who are only able to No Sell certain types of attacks. In that case, the 'weakness' is simply everything except the one thing they're immune to: For instance, a fire demon's immunity to fire has the Kryptonite Factor of 'anything not fire'. Needless to say, this gives a significant discount to how expensive the ability becomes, moreso if the immunity is fairly obvious (i.e. the demon is permanently on fire).
Late-Arrival Spoiler: The GM's rulebook, Our World, spoils pretty much everything of significance from the first ten books, especially the character listing. Your Story is a bit better about it, but still gives away quite a few things, like that Thomas is Harry's brother, the existence of the Alphas and that they become friends with Harry, and the entirety of the plot of Storm Front.
Linear Warriors, Quadratic Wizards: Because of how damage is worked out, those who use Evocation or Channeling can seriously outpace others as far as raw damage goes. Both the weapon value and attack rolls go into determining damage, and while the average mortal will keep a static weapon value (anything past Weapon:2 is hard to conceal, and anything past Weapon:3 is military-grade weaponry) and boost their skill roll only, spellcasters can increase both simultaneously through extra powers or Focus Items. So while an expert marksman of a cop might be rolling from a 5 to fire his Weapon:3 rifle, a wizard at the same level could easily be rolling from 6 to fire off a Weapon:6 fireball, and can get even stronger with subsequent milestones. With enough bonuses, the spells can be an Always Accurate Attack to most enemies.
Luck Manipulation Mechanic: You have the option to spend a Fate Point in order to reroll all the dice in a given exchange if you really blow the roll, or your opponent rolls exceedingly well. This is meant to represent the character's mortal free will asserting itself.
Male Gaze: Of a sort, probably explained by the idea that Billy is working from Harry's case files. Nearly every description of the canon female characters (such as Mab, Lea, Bianca, and Molly) will include a...generous physical description. This might be more Billy than Dresden in some cases, as the latter calls the former out in the margins for referring to Molly as "stacked."
Hypocritical Humor: Which is no worse than the ways Harry describes her; to wit in Cold Days he says "I'd seen her naked once, and she was really good at it."
Master Swordsman: Shiro of the Knights of the Cross is said to be an artist with his blade. The RPG codifies this, giving him a Weapons skill of 6, with stunts to boost it further in certain situations (for reference, skills top out at 4 or 5 for most non-wizard, non-"Plot Device level" characters), and on top of that, one of the powers of his sword gives another +1 to hit when it's in keeping with its true purpose. His profile outright says if you try to take him on one-on-one, you're going to lose. Even Nicodemus, who hates Shiro, grudgingly respects Shiro's abilities
Mooks: No-name enemies are considered this, and the GM is advised to give them middling to fair skills, but only the basic two-box stress track and no consequences, meaning nearly any successful attack with a weapon will take one out.
Mr. Exposition: The game has Exposition and Knowledge Dumping, a Trapping (sub-skill) of Scholarship; on a successful roll, the Game Master can "borrow" the Player Character to use as a mouthpiece to Info Dump about the relevant subject. This effectively cuts out the middleman effect witnessed in most RPG knowledge skill checks (Player 1 rolls, GM relates info, Player 1 says "I tell everyone else".)
Nominal Importance: Discussed in the section on creating NPC's. When the narration mentions that most minor NPC's won't need names, Harry protests that they're still people and have names. Billy then asks why Harry doesn't put everybody's names down in the casefiles. Dresden responds that he often doesn't have time to ask, partly because so many "NPC's" are trying to kill him at the time. Later on, in the character listing, Harry notes that he seems to be really bad at getting peoples' full and real names, preferring to give them cutesy nicknames (like "Spike" for a thug with spikey hair), and concludes that this might be considered a flaw in a detective.
No Saving Throw: Averted for the most part, but still possible to pull off. The books are explicit that you always get to roll defense; backstabbing, blocks and maneuvers might reduce the defense roll to nothing or lower, but you always get to roll. However, some spells and attacks, such as a high-powered Entropy Curse, have attack rolls so high that even with the best defense roll, the target has no chance of avoiding its fate.
Oh Wait, This Is My Grocery List: One set of marginalia is a list of items Harry needs to pick up when he goes shopping. Another has him having jotted down something involving a case. Billy questions him on this, and Harry replies it was just the only piece of paper he had handy when the phone call came in.
Our Monsters Are Different: The "Our World" rulebook has every kind of monster seen in the books up through Small Favor, completely with descriptions and stats in most cases.
Painting the Medium: The rulebooks are full of marginalia where Harry or Bob has made some comment about the contents, as well as the odd sticky note, and there are a couple sections Harry crossed out in Sharpie (which, if you have the PDF, can be highlighted and copied into a word-processor to read them). In one place, he had just grabbed the nearest piece of paper to write on and the details of a completely irrelevant minor case are scribbled in the margin, and in another, he accidentally got his grocery list mixed in (it had "Lawn gnomes" on it, for some reason). The pictures are all a little crooked because they have been sticky-taped in and the "weathered paper" background that seems to be contractually obligated for tabletop RPG books is because Billy dropped it in a puddle while in wolf form. It is wonderful.
Plot Device: A handful of characters are described as being "Plot-Device Level" characters, either because they're so powerful that no Player Party will ever have a chance at taking them on directly (the Archive, the Faerie Queens, Dragons, God, etc.), or because they're so far on the low end of the power scale that they're only able to serve one specific purpose (the tiny pixie Elidee, who appeared in one book to act as Harry's guide/flashlight for a handful of scenes).
Point Build System: The Refresh system of buying powers is one of these. Depending on the level of the game, there is a limited amount of Refresh that a character can spend to buy powers and stunts, and a PC must have at least 1 refresh left over to remain a PC, as that represents a mortal's free will—at 0 refresh and below, a character is totally at the whims of his or her aspects, and unable to act outside of their nature.
Rage Against the Author: After having his "character" used as an example repeatedly, Harry starts to complain about what a dick his GM is, and demands retroactive fate points because of all the crap he's been dragged through.
Rocket Tag Gameplay: The combat system lends itself to this, as it really doesn't take much damage to wound or take out an opponent (barring the variousToughnesspowers), and wounds just make it much easier to finish someone off. As a result, it's rare for combat to take more than a handful of turns to resolve.
Rule of Cool: The books advise that GMs take these rules into account regarding invoking aspects for effect. Specifically, it says that if an invoke makes the game cooler and more fun for the group, it should be a lot more likely to work.
Rule of Drama: The book explicitly says that accepting Compels for fate points should be encouraged, because they generate drama, and drama is good and without it, the game would be boring. Harry disagrees, saying that he loves boring, and could use a lot more of it in his life.
Rules Lawyer: By the write-up of the Unseelie Accords, the treaty by which the various supernatural nations and high rollers can negotiate without going straight to killing each other, Harry and Billy point out that there's no "spirit" to the accords, only the letter of the law, and specifically note that Queen Mab, who wrote them, is very much a Rules Lawyer.
Rule Zero: Referenced here and there, where Billy and Harry have discussions on how a given rule or power ought to work. Some of them end with Billy saying that while he wouldn't run the game that way, it's ultimately up to the GM how it works.
Running Gag: A handful; whenever something from the Blood Rites case (where Harry was working at a porn shoot) is mentioned, Bob pipes up, asking whether someone can give him some "research material". Likewise, in the index, "Shut Up, Bob" is one of the longer entries, as is "Jerks". The last is lampshaded in the margin comments, when Billy calls Harry out for calling a lot of people jerks, to which Harry responds, well, he meets a lot of jerks. Also, one carrying over from the books is Harry's infamous, "The building was on fire, and it wasn't my fault", which is counted as one of his Aspects.
Serial Escalation: On a mundane note, the rules suggest being very careful with how often you hand out character progression, as your PCs can otherwise end up steamrollering all of their opposition before they've really finished their story arcs.
Shout-Out: One possible side effect of necromancy is arrogance "turned up to eleven."
Will: Why donít you just make eleven more arrogant and make eleven be the top number and make that a little more arrogant?
Harry: ...these go to THIRTEEN.
Shrug of God: Since the books are written from the perspective of Dresden and Billy, a handful of the stat blocks and character sheets are specifically noted as "pure speculation" on their parts—Miss Gard, for example, is noted as probably having a catch for her healing abilities, but they're not sure what it might be.
Unbreakable Weapons: The Swords of the Cross and other Items of Power are explicitly unbreakable, and can only be destroyed through a dedicated ritual.
Unreliable Narrator: In-universe, Billy calls Harry out for the various mistakes in his case files, such as giving Wrigley Field a parking lot in one of the books. Also a teasing out-of-character Take That to Butcher, for the same error.
Walking Tech Bane: In addition to codifying the main series' trait of having wizards be these, hexing technology without any other supernatural powers is a power on its own. It's mentioned that there's no documented evidence of this in the series, but Billy justifies its inclusion by saying his mother seems to break any computer she comes in contact with and he's pretty sure she's not a wizard.
You Cannot Grasp the True Form: Why Billy makes no attempt at providing stats for the bigger supernatural entities, like the Faerie Queens or Angels. Also notable is Kincaid's entry, which provides estimates of his abilities under the assumption that he is a Pure Mortal. However, it is noted that whether or not that's really the case, the provided stat block is a very conservative estimate.