In action, adventure or drama shows, the protagonists need a Call to Adventure. Every. Single. Episode. In a series with low seasonal fluidity, a single call may last for an entire series, or at least a few episodes. But if Failure Is the Only Option, then don't be surprised to see a Call happen once a week. Originality is hard, so expect to see writers fall back on the same Call frequently. When the same Call comes on a semi-regular basis or even every episode, this is a Regular Caller.
When done well, it ties into the premise of the show and follows logically, and when done poorly it comes off as contrived and risks breaking suspension of disbelief. This trope is ubiquitous in things like Police Procedurals, Medical Dramas and Courtroom Dramas.
The Magnetic Plot Device can overlap with the Regular Caller, however the Magnetic Plot Device is usually just an in universe justification for the Regular Caller. The Bat Signal is one specific kind of Regular Caller. Compare Prophecy Pileup, when this happens with prophecies related to a Chosen One.
- In Puella Magi Madoka Magica, Kyubey is insistent to the point of being annoying on the whole 'Sign a contract with me and become magical girls' thing. Even when the girls are witnessing horrifying and traumatic things happening to those who decided to sign such contracts!
- In Cowboy Bebop, the Call usually comes in the form of a bounty that needs hunting. Sometimes the Caller is Big Shots, but just as often they've already found out about it through other channels and Big Shots just handles the exposition (and Plucky Comic Relief).
- In Sam & Max and its various adaptations, every case is preceded by a call from the mysterious Commissioner.
- In the Silver Age, Superman often received a Call to Adventure in the form of Jimmy Olsen's signal watch. That, or Perry White would send him to investigate something as Clark Kent.
- As mentioned above, the Bat-Signal is a classic example.
- Plutona has a direct line from the Commissioner that he uses when the city needs help.
- In The Dresden Files, there seems to be some supernatural crisis occurring on the streets of Chicago every six months or so. Of course, this is eventually justified in that many of these events were apparently due to the REAL Big Bad's (whoever that or they are) Evil Plan to...we're not entirely sure yet, make Harry's life a living hell? It helps that Harry has mentioned that magic and dark forces have been getting stronger of late.
- In the Eternal Champion stories, Ekrose (a.k.a. Elric) is always called to a different war on a different world, only getting some measure of peace for a short period of time.
- Harry Potter gets a new call every year, and it almost always has something to do with the current Defense Against the Dark Arts teacher. (The reason the subject gets a new teacher every year is finally explained toward the end of the series: Tom Riddle put a curse on the position after he was turned down for it himself, so that whoever got the job would have something unpleasant happen to him.)
- In Wearing the Cape, Crisis Aid and Intervention Heroes (the setting's city superteams) aren't patrolling freelance crimefighters. Instead they are special services contractors tied into a city's emergency-response department, and most of Hope/Astra's action-scenes start with a summons from Dispatch.
- Michael from the Knight and Rogue Series finds one grand adventure (a.k.a. some crime to investigate) per book.
- In the Young Wizards series the god-like Powers That Be will usually manipulate things so the wizards will stumble upon whatever it is they're needed to do, though occasionally the wizards are given direct orders.
- Though it's never stated outright, there are hints that Indra in Geoph Essex's Jackrabbit Messiah is the god of the Call - right down to a phone call itself being his initial method of prodding the protagonist into the plot!
- Quiller usually starts a novel being coaxed or conned into taking a mission by various directors of the Bureau. This is perfectly acceptable to him, as all shadow executives are Blood Knights and their superiors are expected to be Manipulative Bastards.
- In Stargate SG-1, the main Regular Caller is referred to as an "Unscheduled Offworld Activation". The Unscheduled Offworld Activation happens in almost every episode (except clip shows). The other main one is the Asgard beaming one of the main cast members aboard their spacecraft and requesting their assistance, usually while they are in the middle of something important.
- Charlie's Angels. "Good morning, Angels!"
- Mission: Impossible. "Good morning, Mr. Phelps."
- UFO. SHADO sprang into action whenever SID (Space Intruder Detector) detected a Flying Saucer approaching from space.
- Seven Days: The first indication the Chrononaut project has that there's a problem they need to deal with is Frank Parker and the Sphere both disappearing—because they've just arrived somewhere else from seven days in the future, and they can't exist in two places at once.
- Burn Notice: Every single week early on in the series, Michael is either tricked, guilted, or goaded into undertaking a mission that has nothing to do with himself. More recently his sociopathic "handler" just hands him missions.
- Chuck: The General gives the team their missions, usually.
- Or Chuck will happen to flash on something relevant and then the General gives the team their mission. Although this was common at the beginning, it petered out to the point where it hardly happens at all after he gets the Intersect 2.0
- Quantum Leap had Sam simply Leap into a new time period when he was done fixing the last one. Oh boy.
- Leverage: An aggrieved party usually seeks out the services of the team.
- NCIS: Another dead Naval officer.
- Doctor Who:
- In Series 5, has started having literal calls to adventure, when the Doctor gets a phone call in the TARDIS from some other part of space and time. Winston Churchill has done it twice (the second time getting re-routed to River Song because the Doctor didn't pick up), and so has an unnamed monarch calling about "an Egyptian goddess loose on the Orient Express. IN SPACE!."
- This isn't the first time; Martha gives the Doctor her phone at the end of the Series 3 finale "Last of the Time Lords" for precisely this reason.
- Bonus points since the TARDIS is Mode Locked into a police callbox.
- According to Steven Moffat this was due to Executive Meddling, as the BBC execs were unfamiliar with the Contrived Coincidence of the Doctor always turning up at the right time to stop an Evil Plan.
- Filmation's Ghostbusters, the original Live-Action TV version : "Good afternoon, Ghost Busters. This is Mr. Zero..."
- Person of Interest: the team is sent the Social Security Number of either a victim or a perpetrator of an upcoming violent crime. In Season 2, this trope is revealed to be literal: the Machine uses payphones to relay the numbers.
- Danger 5 are briefed by the eagle-headed Colonel, who for some unknown reason insists on bullying Ice Queen Claire as a Running Gag.
- Short lived Kirstie Alley & Greg Evigan series, Masquerade was sort of a Mission: Impossible on a budget mixed with The Love Boat. A CIA type agency had all its agents exposed so the head of the agency would have the stars recruit a new team of civilians with relevant talents played by a group of guest stars.
- Captain Scarlet and the Mysterons has the Mysterons announce their latest plot to Spectrum, prompting the episode's adventure. Sometimes Spectrum's reaction to the warning is a key part of the Mysterons scheme.
- Every couple generations, The Legend of Zelda's Ganondorf tries to take over Hyrule. Coincidentally, every time he tries, there's a green-shirted elf around who is the only one able to stop him. Specifically, he's sometimes the Hero of Time, but more recently he's going as The Wind Waker, or, "The Hero Formerly Known as the Hero of Time." There's only one exception to this rule.
- "Reimu, you must investigate the scarlet mist!" "Reimu, you must investigate why Spring Is Late!" "Reimu, you must investigate the false moon!"...and so on. Justified, since if it's not for Yukari's (or Marisa's) once-per-episode urging, Reimu will never do her job. It's All There in the Manual, though.
- Adol Christin of Ys. His attitude can be summed up by: 'Ok, saved this place. Time to go look for the next place in need of saving.' While he often finds or is granted magical talismans by grateful locals and goddesses, he either returns them when he's done with them or they fall victim to his bad luck with ships. He's done this seven times, not counting spinoff and Alternate Universe / Canon Discontinuity games.
- Batman: Arkham Asylum and Batman: Arkham City features Oracle, Batman's Mission Control who he contacts on a frequent basis, but the real caller is Joker in Arkham City. Deconstructed when it turns out that calling Batman so frequently is part of his (somewhat successful) plan, because by intentionally giving away hints and playing on Batman's detective mind, he actually succeeds at "[hiding] something from the World's Greatest Detective" by making the truth look like it was too easy to guess to be the logical answer, "dangling it in front of him, right under his big pointy nose", and so Batman failed to realize in time that Joker had a REALLY hammy decoy. The result is that Talia was grievously, maybe even Lazarus-can't-save-them fatally, wounded - and so was Joker.
- The whole premise of The Inexplicable Adventures of Bob! is to Lampshade this. Bob is always minding his own business when some new "call" comes completely out of nowhere and for no apparent reason. Most frequently, The Call crashes into his roof.
- Inspector Gadget would always get an assignment from Chief Quimby in the form of a self-destructing telegram. He would then always assure Quimby "Don't worry, chief, I'm always on duty!" before marching off to duty, only to throw the telegram away so that it literally blows up in the Chief's face.
- Futurama has Professor Farnsworth say "Good news, everyone!" to his employees. It's usually Blatant Lies.
- Thunderbirds has Thunderbird 5 monitoring worldwide communications, to allow them to react to emergencies even though they were a secret organization with no method of direct contact.
- Super Friends (1973-74). The title heroes were called into action by either (a) an emergency signal from the TroubAlert computer, (b) a message from Colonel Wilcox or (c) both.
- The Powerpuff Girls has the team being called by the mayor and a phone with a flashing red light going off.
- 'Hey Wade, what's the sitch?' from Kim Possible pretty much kickstarts every adventure.
- Every time the alarm goes off on Time Squad. In one episode, it doesn't go off for several months, which the team is initially happy about since they just got off a particularly rough mission, but then boredom starts to drive them crazy. Eventually, they figure out that the alarm was broken and that they've actually accumulated a huge backlog of missions.
- Wonder Pets: "The phone, the phone is winging...there's an animal in trouble!"
- In SWAT Kats, Deputy Mayor Callie Briggs has a communicator to summon the titular heroes.
- Except for two or three episodes, where they see what's happening on the live news with Ann Gora, and scramble at seeing it.
- In Walter Melon, being called to adventure happens once or twice every episode. The "protagonist", Walter Melon, an out of shape, far from brilliant "hero for hire" is usually called on the phone by a very poorly disguised pastiche of the actual protagonist from a movie or TV series when they cannot finish their adventure themselves, and hired to do it in their stead. He accepts all major credit cards.
- In every single episode of Phineas and Ferb, Perry the Platupus (aka Agent P) gets orders from Major Monogram to investigate the suspicious activities of Dr. Doofenshmirtz.