A particular group has been tasked a certain mission or project. This group can be as small as a single unit, or even a single man; it can be as large as an organization, an institution, a government, or a group of nations. In all instances, their original purpose was a particular task or mission, and they proceed to carry out that task, and here's the crucial thing, they succeed. At first anyway.
Mission Creep is the problem that begins after initial success. You see sometimes, success is not enough, it turns out your original goal was a woefully small part of a larger problem. Alternatively your solution can only solve that problem temporarily but you are unprepared at providing a long-term solution. In this instance, the original group decides to start expanding and takes on other goals and tasks to supplement their original goal. The original goal is still the main story quest for them, but along the way they find some fun side-missions that buttress their original goal. Initially, it seems that the group can handle these tasks and responsibilities but over time, tensions seep in because of the gap between original project and new responsibilities and without some way to address that gap and come to terms with the change from expectations to reality, mission creep can backfire, destroy or finish the group.
In short, it's the institutional and professional equivalent of a Greek Tragedy. Complete with promising beginnings, tragic inevitability, hubris, hamartia and resignation. It can lead characters to question whether their original goal and so the effort they expanded in that project was really worth it alternatively, characters may decide that their original idea was too vague and unclearly defined, or simply Entertainingly Wrong based on a non-malicious misreading of a situation, but now they have to adjust with a clearer approach to the problem.
Mission Creep is similar and related to Motive Decay, with the difference being that the original motives and goals still exist in some form. In cases where it is closest to decay, the goal becomes The Artifact, but other instances exist of that goal still being primarily the main purpose but now intricately entangled with other related and/or separate goals, new responsibilities and unintended consequences. The Other Wiki has an article on Mission Creep noting that originally it applied to military operations in The '90s which gradually became more and more complicated forcing planners to constantly update and alter initial plans to better serve the original goal but eventually facing up to inadequacy in completing the original task within its current framework. It has since been applied in many non-military situations to describe problems and roadblocks in the life-cycle of any group or mission.
- Alan Moore's Watchmen dealt with the fact that superheroes who sign up to "fight crime" and "save the world" will eventually face issues when saving the world means taking a stand against the government that they ostensibly serve. Part of the drama about the grounded take on superheroes is the poignancy of what heroes do, or what they become, when there aren't bad guys and supervillains to fight and they have to take on real problems.
- Most of the superheroes become detached, depressed and disillusioned when they realize that their pretenses of fighting crime have been fruitless, meaningless or in the case of Nite Owl I, irrelevant, when an actual Physical God like Dr. Manhattan shows up. Their neuroses comes from the fact that they can't match the responsibilities of a changing world, while the one person, Rorschach, who proceeds as if nothing has changed, devolves into a Sociopathic Hero with Black and White Insanity taking pride in his "refusal to compromise".
- In the backstory, Ozymandias attempted to form a super team called "Crime Busters" in the hope of better solving street-level crime. The Comedian then reminded him that it's meaningless in the fears of the atomic bomb. Ozymandias takes this to heart, and to that end, starts building new resources and facilities so as to eventually save the world, by means of staging a brutal alien invasion that single-handedly ends the cold war and forces the US and USSR to peace in a Genghis Gambit. In Ozymandias mind, he hasn't changed his goal and purpose, merely taken on additional responsibilities and tasks to achieve it.
- Parodied in Austin Powers: International Man of Mystery. The defrosted Dr. Evil returning from The '60s to The '90s tries to launch into an old-fashioned spy supervillain plot only to be reminded that his organization in his absence had to Cut Lex Luthor a Check and branch into legitimate corporate enterprise so as to better serve evil of course.
- Black Hawk Down by Ridley Scott is set during the Battle of Mogadishu which was a Trope Namer when journalist Jim Hoagaland described the term when covering the conflict, and it's tragically illustrated in a film about soldiers finding a reality that severely complicates and compromises their brief. The film displays dramatically the manner in which a seemingly normal mission quickly gets severely complicated.
- Lawrence of Arabia has the titular T. E. Lawrence serving as a British Officer in the Middle East opposing the Ottoman Empire in World War I. To better oppose the Ottomans, he is recruited by his superiors (because of his knowledge of the Arabic language and local cultures) to visit various tribes and recruit their support against the Turks. In the process, Lawrence more or less helps to trigger Arab nationalism, as the various warring tribes try and unite in the hopes of forming a nation, and Lawrence buoyed with success hopes to help them secure independence, only to be told by the English that the Sykes-Picot Territory will once again partition the large territory and that once the Turks are defeated, they hope everyone to go home. Lawrence to the end, hopes to achieve both his goals (loyalty to England, and independence for the Arabs) only to overreach, exhaust and burn himself out, to his own disappointment and that of his friends.
- A Song of Ice and Fire has many examples:
- Robb Stark's Northern Campaign begins with the initial aim to rescue his father and his sisters who are held hostage by the Crown. To that end, he lifts the siege of Riverrun and captures Jaime Lannister as a hostage to force an exchange. But at that time, King Joffrey impulsively executes Ned Stark. Robb knows that the Lannisters won't exchange Jaime for his sisters, and that at the same time the other Riverlords oppressed by the Crown look to him as the only force to protect them from the Crown. So they appoint him, and he accepts in turn, the offer to become King in the North and Riverlands, with his new aim being to secure independence for both territories from the Seven Kingdoms. Robb's motive of revenge against the Lannisters doesn't change but circumstances provide him additional responsibilities to achieve that, which tragically backfire when he fails to reconcile his original purpose with his new responsibilities.
- Daenerys' overall purpose is to return to Westeros with her three dragons and reclaim her birthright. The manner in which she seeks to achieve that goal however leads her to take additional goals and ideals along the way, even if she, to her mind, has not changed her original purpose. A need for her own army, leads her to follow Jorah Mormont's suggestion to purchase Unsullied, slave soldiers, whose treatment so appalls her that she spontaneously sets forth on an abolitionist campaign and conquers an entire region of Essos, and ends up becoming ruler of three. However, upon achieving this, she realizes that the consequences of her actions would need her to stay back and rule her conquered territories especially since her control over her dragons starts to weaken, and The Remnant of the slavers seek to send freedmen back into slavery.
- Robert's Rebellion likewise began with Robert, Ned and Jon Arryn trying to arm themselves to protect them from Aerys II's death warrant. Slowly it expanded to becoming a rebellion to oust a 300 year old dynasty with Robert as King, a position he did not really want, but was more or less expected to accept to better protect the rebels and the soldiers from recrimination. The end result is a long peace managed by individuals with no real ideas on how to run Westeros other than replace one dynasty with other and hope that the rest of Westeros could fall in. This cracks in the Succession Crisis of the War of the Five Kings. It would have all worked out, more or less If Robert's only trueborn heir had survived and/or if his wife hadn't had an affair with her brother
- The Lord of the Rings appoints the Fellowship to carry out a simple mission, escort the Ringbearer (Frodo Baggins) to Mount Doom and drop the One Ring into the lava. But along the way, the fellowship faces setbacks, the temporary disappearance of their wizard mentor Gandalf, the loss of one of the fellowship in battle (Boromir) and the risk that the ring could corrupt other members of the Fellowship into compromising each other. As such to better carry out the mission in complex circumstances, the fellowship breaks up with Frodo and Sam going to Mount Doom alone, while Aragorn, Gimli and Legolas march to rally a movement of resistance to oppose Sauron and Saruman's forces to better distract their attention and draw their gaze away from Frodo and Sam. What starts with a fellowship of nine ends up involving an intricate alliance of human kingdoms, undead armies and eagles, all to serve the same original mission which could never have succeeded had they operated in the way they originally set out to accomplish.
- Assassin's Creed has many characters addressing the issue. While they have been said to exist in some form or the other from before the modern era, the contemporary Assassins descend from the Asasiyun of Masyaf. In a larger franchise sense, the Assassins start out as a secret society dedicated to simply assassinating their targets and opposing the schemes of the Templars. They were originally Warrior Monks who operated in fortresses and specialized solely in assassination. Eventually, the Assassins without losing sight of their goal (opposing Templars and using force as and when necessary), take on additional responsibilities and duties (sponsoring revolutions, helping the local infrastructure, building communities and so on and so forth) that nonetheless creates problems when they try and fail to reconcile the gap between their original purpose and new responsibilities.
Al Mualim: Altair, your mission has not changed. Merely the context within which you perceive it.
- Assassin's Creed I: Discussed many times by Altair, Al Mualim and the various Rafiqs. Altair is told to perform simple tasks (kill 9 Templars) but finds that their motivations and the reasons for killing them, and the connections between the targets hint at something bigger:
- Assassin's Creed III: Connor's general mission is to protect his village and people, but then he receives Juno's message to join the Assassins and protect the Key to the Temple. Connor took this to mean that joining the Assassins and fighting the Templars would help his people. And later, he interacted with Patriots and came to see his causes (Protect his Village, Serve as Assassin) entangled with American Independence. This taking of additional duties complicates his adventures and eventually leads him to confront his overall failure when two of those goals: American Independence and protecting his village, gets compromised by his duty as an Assassin. In the end, Connor came around to Achilles' way of thinking and realized he was too naive and burdened himself with false expectations.
- In the backstory of Overwatch, the organisation the game is named after was formed to deal with the first Omnic Crisis. Afterwards, it became a general peacekeeping organisation, but it also gained a secret "Black Ops" division. When these operations were revealed, public opinion turned on it and infighting between the two sections began. Culminating in both of its top leaders apparently Mutual Killing each other after a confrontation, and the UN disbanding and outlawing it.
- Mike Duncan in his The History of Rome and Revolutions notes that many of the events we associate from this era and from revolutions began on a small limited scope but thanks to circumstances and other issues ended up becoming Disaster Dominoes thanks to groups and individuals taking on responsibilities and duties they were not equipped for and which they do by greatly exceeding their command.
- He specifically notes that the English Civil War, The American Revolution and The French Revolution began with modest aims and intentions and ideally would have been a small footnote had it gone as per the original intentions. But circumstances made a parliamentary protest into a bloody civil war divided by religion and ideology, and in the case of the American Revolution, made a bunch of colonial property-owners into Enlightenment idealists and practitioners moving by Indy Ploy into slowly forming their own country and nation.
- In the case of The Roman Republic and The Roman Empire, he notes that it largely happened because of a failure of the Senate to properly control its army by the end of the Punic Wars, leaving Generals like Scipio Africanus to decide how to pay for their wages, upkeep and remuneration, and forcing politicians, opportunists and reformers both, to start using offices as a path to power and slowly exceeding their command. The end result led to temporary titles like Dictator becoming Dictator perpetuo and imperator becoming Emperor.
- Justice League begins with a group of superheroes teaming up to fight progressively more dangerous threats. To achieve this they build a space station called the Watchtower, their own planes and store alien technology. By the time of Unlimited they expand their roster from 7 to Heroes Unlimited and possess a better space station (with a whole support staff), a fleet of super-jets, and their own BFG in case of emergencies. In the eyes of the Justice League these are merely logical expansions in the wake of Serial Escalation of threats, but this causes problems for them because neutral observers believe they have become a N.G.O. Superpower without any checks and balances, and dangerously close to Jumping Off the Slippery Slope and taking over the world.
- The real life The Knights Templar faced its downfall because of its inability to resolve this issue:
- Their original mission was to protect Christian pilgrims traveling to the Holy Land after the First Crusade, and its initiates were the Poor Fellow Soldiers of Christ, Warrior Monks dedicated to the vow of poverty they took. But in the course of time, the Templars' facilities became respected stopping points where travelers could store their cash and reclaim it at another branch, and they slowly became bankers. They received exemptions from paying taxes from the Church, owned land in various European nations and gradually expanded their operations from their original mission as time passed and their duties became complex.
- By the 1290s things came to a head because The Crusades kept failing to attract royal patronage and favor, other church organizations wanted access to the Templar infrastructure and the Templars were considering forming an independent kingdom. Before they could act on it however, the French King Philip IV brutally purged them so as to better access their treasury and goods.
- The Roman Republic became The Roman Empire because of this. Its institutions and civic patriotic culture worked effectively for a city-state that was more or less Rome, outer-territories and Latin environs, but it was not equipped, at least not without reforms, to deal with an empire that included the Iberian peninsula, parts of North Africa, all of Greece and Asia Minor and all of Italy.
- The Roman expansion and constant warfare led to an excess of slave-labour and weak distribution of land and wealth to the urban poor and poor soldiers. The Senate led and dominated by the Patrician class of Rome had nothing but contempt for newcomers and weren't interested in sharing and distributing power and rights to other Italian cities and clients, leave alone the Mediterranean. The one real avenue of consistent change since the Socii War had been the army, and generals like Marius and Sulla, followed later by Pompey and Caesar, became bigger job creators and wealth creators than the state.
- Still, the slide from Republic to Empire need not have been inevitable had there not been a total breakdown in government, had the institutions shown some flexibility to accommodating reforms. Instead proposed reforms and reformists whether argued by figures who were radical (Gracchi, Cinna) or moderate (Marcus Livius Drussus, Caesar) were met with violent murder and recrimination, and in the end, the Republic's own client-patronage system was used effectively by Augustus to create one-man-rule with the appearance and pretense of a Hereditary Republic.
- This happens all the time with government institutions regardless if its the Empire, a Kingdom or a Republic. Nothing stays the same over a long period of time, and institutional inertia and weak rulers play a major part, and bear a major responsibility, for dropping the ball and refusing to be flexible in time. This is often the main cause for revolutions, and for decolonization and anti-imperialist movements.
- Critics of federal power in the United States Political System argue that this is what happened to the Constitution over time: Originally the Feds were only given a rather limited set of "Enumerated Powers" with everything else delegated to "the States or the people", however, there were two key clauses: First, the Federal government was explicitly granted the power to regulate trade between the individual states and second it was granted the powers "necessary and proper" for the exercise of its enumerated powers. Over the course of the 150 years since the American Civil War, Interstate Commerce has greatly increased and so have the federal laws justified by regulating it. Because after all, if you have to regulate commerce between the states, you also have to regulate the railroads that carry the goods, right? And if you have to regulate the railroads, you also have to regulate the negotiations between railroads and their employees for salaries, right? And if you have to regulate that for railroads, the Fourteenth Amendment indicates you cannot treat a baker different from a railroad worker, right? Similarly, the Fourteenth Amendment is commonly interpreted to implicitly "incorporate" the Bill of Rights (which is usually worded as "Congress shall make no law"...) against the states, thus prohibiting Rhode Island from having a state religion (which it could and Maryland did when the Constitution was passed)
- Many of the companies now having an Artifact Title did originally do Exactly What It Says on the Tin but due to one type of this trope or another now only do what gave them their name as a minor part of their brand or don't do it at all.
- Police, often hamstrung by budget, manpower, practicality, etc. will find itself in such a situation. Suppose there is a spate of assaults, which leads to a full court press and showing the flag as a temporary or band aid solution. And Then What?? They do not have the resources to commit to fighting this specific crime long term. A permanent police presence will only move offenders somewhere else. So how to find a more permanent solution...most are in the unfortunate position of having to scale back to business as usual when it is not a serious or political enough to act on.
- This is one of the main reasons so many engineering and programming projects end up significantly late and over budget. You might start out with a well-planned, properly budgeted project, but as soon as people start requesting additional features or trying to adjust existing ones, costs and timetables start rocketing. Seemingly minor changes can require huge amounts of work to fit into a project once it's started since they often mean having to go back and redo previous parts as well, even if they would have been cheap and easy to do if they'd been designed in from the start.
- In the United States this is called "scope creep" particularly when it happens to public works projects (highways, dams, railroads etc.) and is often cited as one of the main reasons for the exorbitant construction costs in the US compared even to fellow high wage developed nations
- The United States Secret Service was originally founded to eliminate counterfeit money, but now is best known for being the bodyguards for political figures and their families. They still have anti-counterfeit duties, however, and as such the Secret Service was part of the Treasury Department until 2003.