The film has two main parts to the plot. The first part deals mainly with the formation of the band. In the beginning, Jables, a young rocker living in an oppressive, religious household, prays to a poster of Ronnie James Dio, and is given a vision of his future. He is bidden to run away from home to California, where he is to meet his best friend and band partner. After traveling far, he meets this man, Kage, who turns out to be something of a bum wanna-be. Kage gives him extensive rock "training."
The second part involves the two trying to create a masterpiece song to pay their rent. During a jam session, they stumble onto the secret of an ancient rock artifact known as the Pick of Destiny. It happens to be Satan's tooth. The two then go on an adventure to retrieve said artifact, and get into all sorts of trouble along the way.
This film provides examples of:
- Aluminum Christmas Trees: "Kickapoo" might sound like a scatologically humorous name for a fictional town in the Midwest, but there are actually several cities named Kickapoo, named after the Native American nation.
- Animated Credits Opening: The movie opens with an unrelated minute-long cartoon (created by John Kricfalusi, who'd also done their "Fuck Her Gently" video) spoofing the THX logo.
- As Himself: Ronnie James Dio appears as his poster come to life in the film's intro.
- Badass Boast:
- "I DO NOT NEED - (he does not need...) - A MICROPHONE - (a microphone...) MY VOICE IS FUCKING - (fucking) - POWERFUL!!!"
- The open mic host, who is the devil in disguise, gives a Rousing Speech about Satan and how he's responsible for everything awesome.
- Im the devil, I can do what I want
Whatever Ive got, Im gonna flaunt
Theres never been a rock-off that Ive ever lost!
- We will defeat you, Beelzeboss
We know your weakness, our rocket sauce!
We rock the casbah, and blow your mind
We will defeat you for all mankind!
You hold the scepter, we hold the key
You are the devil, we are the D!
- Big Brother Mentor: Kage.
- Big Eater: Kage, who orders fried chicken, steak, and chicken fried steak during the diner scene.
- Big "NO!": Jables lets one out after realizing that the Devil has him and Kage outmatched. By the end of the rock-off, the Devil ends up having an even bigger 'no' while being sent back to Hell.
- Big Red Devil: Provides the page image.
- Birthmark of Destiny: JB and Kage have matching birthmarks, one says "TENAC" and the other says "IOUS D". On their buttcheeks.
- Bittersweet Ending: The pick is gone and Satan isn't paying the D's rent since they lost the rock-off, but they still managed to banish him back to hell and save Kage (and the world). Plus, now they have a different supernatural Satanic artifact: the Bong of Destiny.
- Black Comedy Rape: If Tenacious D had lost the rock off against Satan, Kage would have become Satan's sex slave.
- Black Sheep: JB by his own admission: he's an aspiring rock star in a family of anal-retentive fundamentalist Christians.
- Bread, Eggs, Breaded Eggs: In the diner scene:"Let me have the fried chicken, and a steak, and the chicken fried steak."
- Brick Joke: "Pass the B.O.D."
- Broken Pedestal: Happens to Jables when he finds out that Kage isn't really a rock god, and has been living off his parents for 13 years.
- Call-Back: The D's part in "Beelzeboss" is strongly implied to be the song they refer to in "Tribute", as it gets referred to afterwards as "The Greatest Song in the World".
- The Cameo:
- Neil Hamburger has a very short one as himself, performing at the same open mic night as Tenacious D themselves.
- Meat Loaf playing Jables's dad, and Ronnie James Dio singing as a poster of himself, in the same song.
- Ben Stiller also plays a receptionist at Guitar Center who actually ends up telling the D all about the legend of the Pick of Destiny.
- Amy Poehler as a waitress at the "Halfway House" truck stop.
- Colin Hanks — Jack Black's co-star in Orange County — as the drunken frat boy who pelts Kyle with an empty cup as he's preparing to leave the college party.
- John C. Reilly as Sasquatch.
- Dave Grohl, provided you can spot him under all that Satan makeup.
- Celebrity Lie: Kage lies to Jables and claims that he's friends with the guys in Black Sabbath.
- Chase Scene: "Car Chase City".
- Chekhov's Gun: When the Clerk at the Guitar Center offhandedly recites the translation of the words that sent Satan back to hell the first time, JB apparently remembers it word for word, it comes in real handy later.
- Chekhov's Skill:
- Power-slides and cock push-ups both turn out to be very useful tools for stealing the Pick of Destiny.
- Also, the video game Kage plays gives him the skills to escape the cops in real life during "Car Chase City".
- Chess with Death: Not so much chess as a rock off, and not so much Death as Satan himself.
- Cluster F-Bomb:
Oh the dragons balls were blazin' as I stepped into his cave, then I sliced his fuckin' cockles, with a long and shiny blade!/'Twas I who fucked the dragon, fuckaly sing-fuckaloo!/And if you try to fuck with me, then I shall fuck you too!
- Whenever Jables is improvising song lyrics. Just listen to "Classico".
- Satan's initial boast and reaction definitely qualifies. See Oh, Crap! below.
- Also in "Kickapoo":
- Double Standard: Rape, Male on Male: Suggested between Satan and Kage.
- Dramatic Irony: Meat Loaf, as the very religious dad, punishes young Jables for liking/playing rock 'n roll in the house.
- Duels Decide Everything: Tenacious D engages Satan in a rock-off, the terms being that Satan must return to Hell and pay for their rent should he lose, and that Kage is to be Satan's bitch if Tenacious D loses.
- Eye Scream: One of the Rock and Roll History Museum guards claims to have forced two hostiles to gouge each other's eyes out, simultaneously.
- Fantasy-Forbidding Father: Jables' dad tries to prevent his son from becoming a rock star, telling his son that rock and roll is a corrupting influence of Satan that brings chaos to the world. He is completely right.
- Foreshadowing: Jables' father warned him that the rock music would make him Satan's puppet and bring chaos to the world. He would have been right if Jables and Kage hadn't defeated Satan in the rock-off.
- Fun with Acronyms: "That's where the POD lies now." "POD?" "The Pick of Destiny!" "Oh."
- Greasy Spoon: The Halfway House Cafe.
- Groin Attack: Jack slips and falls, straddling a tree branch. "OW, SWEET BABY!" indeed.
- Groupie Brigade: Seen during Jables' dream sequence.
- Heroic Fantasy: The second half of the movie, when Jables and Kage go after the Pick of Destiny, the plot basically shifts to this. I mean, it's still set in the real world, but all the tropes are there.
- Honour Before Reason: Turns out that even the Devil must abide by the Demon's Code and accept any declaration of a rock-off challenge. However, it appears that he is the sole judge of who wins. Which may be a factor in why he has never lost.
- Intimate Marks: Both Jables and Rage Kage have Birthmarks of Destiny on their hind quarters that spell out "Tenac" and "ious D" respectively. They take this as a sign to name their band Tenacious D.
- Invisible Backup Band
- Ironic Echo: When Jables sees a hot girl walk past Kage's apartment, Kage tells him to be on top of his sexual game because there'll be ten times hotter girls backstage when they perform. Later, when Kage is Distracted by the Sexy at the diner, Jables tells him to forget the sorority girls because there'll be ten times hotter girls backstage when they win album of the year.
- It Was with You All Along: Parodied. When the guys break the POD before going on stage and start crying, the open mic host, actually Satan in disguise, warmly reassures them that they don't need a magic guitar pick to channel the Devil in their music, then gives an inspiring, heartfelt speech about how Satan lives within "all of our hearts", ever tempting us to debauchery and defiance. Jables and Kage find this comforting.
- Jerkass Has a Point: Jack's dad was oppressive & violent but he was right about a few things. "Beelzlebub did pull the strings, Jack's heart did lose direction, & it did bring chaos.
- Karma Houdini: The Droog-like punks who beat up Jables with his own guitar get scot-free.
- Large Ham: Jables, Jack Black after all. And Dave Grohl as Satan.
- Laser Hallway
- Leaning on the Fourth Wall: The duo arrives at the "Halfway House" truck stop about halfway through the movie, as pointed out by the commentary.
- Louis Cypher: The open mic night host.
- MacGuffin: The eponymous Pick of Destiny.
- Manchild: Both of them, but especially Kage.
- Mic Drop: JB knocks the mic stand over after the D's first "concert" (a one-song amateur/open mic night). The audience is not impressed.
- Mirrors Reflect Everything: How Satan is ultimately defeated.
- Momma's Boy: Kage, if his flashback and living off his parents for 15 years is any indication.
- Morton's Fork: The stakes of the rock-off end up being this for Satan. If he loses, he must go back to Hell (and also pay Tenacious D's rent). If he wins, he takes Kage back to Hell as a sex slave. Either way he has to go back to Hell.
- Mundane Made Awesome:
- "It's a sign... a legacy." *proceeds to show birthmark on ass*
- Power sliding past the security guards under the security door.
- Mundane Utility: The stipulations of Tenacious D's rock-off with the Devil is that if they win, the Devil must go back to hell, and also has to pay their rent.
- Mushroom Samba: When Jables gets lost out in the woods, he survives by eating unidentified mushrooms, which results in a trip wherein he becomes a baby sasquatch, and then begins singing about how his dad is awesome and shall protect him.
- Mythology Gag: The D are met by Satan and have to play a song to save their lives (and the world). After surviving, they are unable to remember the kickass tune they played, so they try to rewrite it from scratch. Mayhaps a "Tribute" to that song?
- Nice Job Breaking It, Hero!: Literally, breaking it: Jables and Kage fight over the pick and break it in half. It then gets picked up by the devil, and the shit immediately hits the fan.
- No Indoor Voice:
- Jables ends up daydreaming that with the eponymous pick, his voice will become so loud he will lose any need for microphones.
- Also, Satan. All the time.
- No-Sell: After Tenacious D bust out their best Power of Rock song against Satan in their rock-off, Satan just says "You guys are fuckin' lame!" and declares himself the winner.
- Nobody Here but Us Statues: Jables and KG act as statues in the Rock and Roll History Museum to hide from a guard.
- Oh, Crap!:
Satan: I AM COMPLEEEEEEEEETE!
- The song that plays when Satan gets the pick:
Tenacious D: Fuuuuuuuuuuu-uuuuuuuuuuuuuuuuuuuuuck!
Satan: YES, YOU ARE FUCKED! SHIT OUT OF LUCK!
NOW I'M COMPLETE, AND MY COCK YOU WILL SUCK!
THIS WORLD WILL BE MINE, AND YOU'RE FIRST IN LINE!
YOU BROUGHT ME THE PICK, AND NOW YOU SHALL BOTH DIE!
Jables: Waaaait...waaaaait! Waiiiiit, you muthafucka! We challenge you to a rock-off! Give us one chance to rock your socks off!
Satan: FUCK! FUCK!! (dramatically) FUUUUUUUUUUUUUUUUUUUCK... THE DEMON CODE PREVENTS ME...FROM DECLINING A ROCK-OFF CHALLENGE...
- Kage gets one early on when his mom's voicemail message exposes him as a fraud to Jables.
- Kage gets another one during Satan's Rock Me, Asmodeus! when he reveals his collection of BDSM gear. Watch the look on his face switch from "awesome performance" to "I'm screwed" in a split second.
- Satan gets yet another one when after accidentally blowing off his own horn, he realizes that he has given Jables a way to send him back to Hell.
- Parental Favoritism: "You disobeyed my orders son, why were you ever born?/Your brother's ten times better than you, Jesus loves him more!"
- Plot Hole:
- Pointed out in the DVD Commentary by Jack, during the training montage, Jables collects $10 worth of coins in a cup while performing on the boardwalk. How can he assume he collected ten exact bucks just by looking into the cup?
- Soon after in the same scene, Jables goes to a nearby payphone and uses 10 cents from the cup to call Kage at home, making it $9.90. Would Jables still have enough money for the dime-bag he obtains after this scene?
- Rock Me, Asmodeus!: Parodied, especially with lines like "I'm the devil, I love metal!". Maybe played straight as well, considering that, yes, the Devil really turns out to be the greatest metal musician of all time.
- Rule of Cool: Overused in the songs to the point that it becomes funny how much it's overused. Particularly in the Master Exploder dream sequence.
- Rule of Funny
- Satan: Appears as the final boss which the titular duo have to defeat in a rock-off challenge. They lose, because the Devil is really just that good.
- Sex, Drugs and Rock & Roll: During the reunion, Kage says it was supposed to be in that order. Kage goes off to a party, Jables into the forest and eats mushrooms, and then they both get the Pick together.
- Shock and Awe: Satan's favoured method of attack in this movie, instead of the fire-based moves one would normally expect from him. He still seems to come from Fire and Brimstone Hell, though.
- Shout-Out: The Devil's guitar is Dimebag Darrell's famous lightning bolt Dean ML.
- Sir Swears-a-Lot: Satan, unsurprisingly. JB and KG, to a lesser extent.
- Slasher Smile: Jack Black shows his off a few times, revealing that it looks like a cross between the Joker and the Grinch.
- Small Name, Big Ego: In "History", the guys boast about being a godlike rock band that has performed all sorts of outrageous feats. The audience reaction is lukewarm at best.
- Sophisticated as Hell: "Classico" is basically this trope in music form.
And fucking roll, out of control
Well, then you know you've got to rock the block
And fucking suck my fucking cock
'Cause when you rule, you fucking school
All of the fools out of their jewels
'Cause if you think it's time to, if you think it's time to, if you think it's time to fucking rock...
- Stoner Flick: The audience is now baked.
- Stoners Are Funny: The movie has several gags revolving around drug use. The funniest is probably Jables' mushroom-induced hallucination.
- Tarot Motifs: The opening sequence is based around them.
- The Guards Must Be Crazy: As in, they're all smoking weed and not watching the security cameras while Jables pulls what is possibly the single least stealthy attempt at a covert break-in in history.
- The Quest
- The Power of Rock: Obviously. Taken to ridiculous extremes in "Master Exploder" and "Beelzeboss (The Final Showdown)".
- Un-Duet: KG ends up performing one of Tenacious D's songs to find he only remembers his lines, which are mostly just for backing.
- The Unfavorite: Jables (see Parental Favoritism).
- Unnecessary Combat Roll: Jables does some while breaking into the Rock and Roll History Museum, and yet the camera continues to see him (and only the camera).
- "Well Done, Son!" Guy: Jables shows signs of being this.
- When You Snatch the Pebble: "When you snatch the remote control out of my hand, you will have earned the right to change the channel."
- Wowing Cthulhu: Subverted. After the D put forth their best effort in the rock-off, the Devil just says their song was "fuckin' lame".
- Writing Around Trademarks: The Rock and Roll History Museum.
- Your Head A-Splode: In the "Master Exploder" Imagine Spot, Jables causes a man's brain to fly out by singing epically.Jables: "I did not mean . . ."Kage: (He did not mean)Jables: "To blow your mind!"Kage: (To blow your mind!)Jables: "But that shit happened to me . . . all the tiii-yiii-hiiiime!"
- You Have GOT to Be Kidding Me!: Satan's reaction when Jables challenges him to a Rock Off, knowing he can't refuse it.
- Your Princess Is in Another Castle!