Magic Tool

A universal, mundane-looking, multi-purpose hand tool whose user can magically fix any machine or structure without raw materials or effort, simply by waving it at the target from close range. Surprisingly, it is often not much use as a weapon.

Carried by the universal Worker Units in Real Time Strategy games, and the Engineer classes in team-based First Person Shooters.

Compare Green Rocks, Duct Tape for Everything and Green Lantern Ring. For one of these that can break things instead of fixing them, see Swiss Army Weapon. Not related to ancient artifacts of tremendous power.

Comics

 * The omnicoms used by DC's Legion of Super-Heroes resemble iPhones with all manner of scanning/sensing and computing capabilities, although they actually predate the iPhone (and the cell phone, and the laptop computer) by several decades.
 * Steelgrip Starkey and The All Purpose Power Tool was centered around this trope. It's the size of a toolbox, but can be programmed to perform any task, from raising a skyscraper to clearing a polluted gulf. It runs on no visible power source, synthesizes new components and materials out of thin air, and is apparently indestructible.

Film

 * In Six String Samurai all that is needed to fix a car is a ratchet, cranked a few time on the dashboard. This may have been intentional, as the rest of the movie is pretty ridiculous, too.
 * All mobile phones of James Bond. Taser, remote control for your car and hacking/lockpicking skill of 5000. Magic! Averted in Casino Royale and Quantum of Solace, where the phones are just, well standard phones. Product Placement ensures we get a good long look at them.

Literature

 * Mischief In Maggody: Non-scifi example: Joan Hess played with this trope when Kevin gets a job selling vacuum cleaners door-to-door. The brand he's selling apparently does everything from regular vacuuming to leafblowing to paint-stripping to scaling fish. Heaven help whoever has to clean out the vacuum's filters and dust bag....

Live Action Television

 * In Doctor Who, the sonic screwdriver is a piece of Applied Phlebotinum that can basically fix, break, lock, unlock, or otherwise modify anything you want. The only things it specifically can't do are unlock a deadlock seal, inflict injury or kill. Unless you're a Cyberman. Oh, and it doesn't work on wood. And it's vulnerable to hair dryers. And you can't triplicate the flammability of alcohol either. It may not be able to inflict injury, but if you're dumb enough to let him near the sound system it can sure as hell hurt your ears. Oh, and one time, it was used to drive a screw.

It's also utterly useless as a conventional weapon -- the Doctor wouldn't carry it overwise, as he has moral objections to carrying weaponry. The Master has been known to carry a 'laser screwdriver', a similar multifunction tool which is weaponiseable.
 * Then the Eleventh Doctor appears to use it as a weapon against the Silence, while River Song is shooting them. The screwdriver emits a green beam as he whirls back-to-back with River, but he's simply using the screwdriver on the ship that surrounds them, preventing the Silence from absorbing it to power their attacks.
 * Star Trek the Original Series
 * The Tricorder and related items, which often allow a skilled user to discover, diagnose, and fix almost anything with no other tools.
 * "Assignment Earth" was a Poorly-Disguised Pilot for an Avengers-esque spinoff series. The protagonist of that episode, Gary Seven, had a do-anything gadget called a 'servo' which is sometimes suspected of being a direct ripoff of the Doctor's sonic screwdriver (it even looks almost identical), but which couldn't have been because the sonic screwdriver didn't make its screen debut until about a month after "Assignment: Earth" was filmed, and more than a year after Gary Seven's servo was first proposed in the original unsold pilot script for Assignment: Earth. Not to mention that Doctor Who wasn't seen in the US until the '70s.

Tabletop games

 * Although not strictly a tool prestidigitation has the most functions of any single spell.

Video Games
"Continue swinging wrench in an aggressive manner in the direction of your sentry in order to extend dual rotational barrels and remove rear lid from ammunition housing container."
 * Starsiege Tribes: The Repair Backpack. Point it at a friend, hold down the trigger, and watch a red laser thingy heal him back up to health. Turn around and use the same laser thingy to repair a crushed generator to perfect condition. You can also used it to repair enemy equipment and players.
 * War Craft
 * The axes used by human peasants and orc peons in the games can chop wood, fix buildings and repair siege equipment, and chop up enemy infantry, if you gang up on him.
 * Averted in the third game, where the workers use different tools for building or gathering wood. Human peasants can also be temporarily turned into stronger milita units to defend, while the peons can hide in bunkers and shoot from inside.
 * World of Warcraft: the Gnomish Army Knife is a straight example of this trope. Created by high level engineers, this device give you the functionality of a blacksmithing hammer, skinning knife, screwdriver Gyromatic Micro-Adjuster, Arclight Spanner, and a mining Pick. Also, has a function to bring a player back from the dead, if you are a skilled enough engineer. Originally had a option for flint and tinder in order to create camping fires, but the need for them was removed from the game entirely and from the item specifically.
 * The wrench from the Battlefield series is a miraculous device. Just grind it on any vehicle, destroyable object, or bridge to repair it. Surprisingly, it cannot be used to bash in someone's head, or sabotage enemy vehicles.
 * Battlefield 2142, in keeping with its theme, replaces wrenches with a repair-gun/welder device, but it has the same functionality as the wrenches of previous games. You still can't hurt anyone with it.
 * The "Power Tool" in Battlefield Bad Company will repair any vehicle if held up to it and spun. It will also kill enemies if ... held up to them and spun.
 * The second usage is quite possibly more sensible than the first. After all, having a spinning power tool shoved into your face would likely hurt.
 * Starcraft has a more "realistic" depiction, for the Protoss and Zerg, since neither really builds or repairs their structures. Protoss teleport theirs from their homeworld, and the Zerg buildings are living organisms grown from the ground by converting a harvester unit into a cocoon.
 * One could argue that the SVC isn't all that unrealistic either. The "Fusion Cutter" is a reasonable tool for harvesting and not implausible for emergency combat, and you'd expect that it'd be used as a welding tool during construction/repair. Since the unit is actually Powered Armor, it probably carries more tools than just the Cutter for construction. Now how it gets the construction materials to your beachhead halfway across the map is another question.
 * The Elder Scrolls III: Morrowind and The Elder Scrolls IV: Oblivion have Repair Hammers, good for fixing all swords, bows, armor, hammers, axes, daggers, and shields.
 * Some official mods in Oblivion add forges and other such things which boost your Armorer skill when you're near them, which seems to imply that the Repair Hammers are imperfect at their job unless the player is a master at the craft.
 * Everyone always forgets about Morrowind Repair Prongs. Seriously, how did those repair anything?
 * You hold stuff with them so you don't, for example, break all your fingers with a lump hammer.
 * Oblivion had a skill book that explained how hammers could be used for repairing most pieces of armor. Though it suggested that needle and thread would be more useful for fur and leather, and advised care when repairing glass armor
 * Engineers in Enemy Territory Quake Wars have a pair of pliers that can be applied to any part of any machinery, even if the player is lying prone and only able to reach a support leg. The pliers are almost as effective as the Contructor's futuristic repair tool (although they also have an automatic droid).
 * While no one save for the developers at Treyarch know what it would have done, it's worth mentioning a canceled perk for vehicles for Call of Duty: World at War was called 'Magic Wrench'. Presumedly, it would be used to repair tanks.
 * The Engineer's wrench in Team Fortress 2 is an exception to the rule: you can brain people with it. In fact, one repairs a structure or upgrades a sentry gun by whacking it with the wrench. The game's "manual" hangs a lampshade on the practice, as it's actually an instruction booklet on Sentry Gun maintenance. The instructions on upgrading the gun say, for example:


 * In Star Wars Battlefront II, the engineer's fusion cutter can fix destructible objects, disarm mines, and cut into enemy tanks to hijack them, but not cut open an enemy.
 * Command and Conquer spinoff Renegade features the Repair Gun, which has some range unlike most variants, and does exactly what the name implies. They can also disarm enemy C4 and beacons by draining their health bar (nothing else can damage these things). The singleplayer version is only used by NPCs and has a damaging secondary fire, but not so the multiplayer version.
 * Mass Effect has the appropriately named Omni-tool, a holographic tool that can dispense medigel, conduct electronic warfare, and function as a datapad, and repair vehicles and a certain plasma vent. It is also a definite threat in combat; if you bring her along, the tech-focused party member will brandish one as a threat while others draw weapons or take up their Pstandard Psychic Pstance.

In the game's codex, it's explained that the Omni-tool's functionality is provided by downloadable programs, and that its miniature nano-assemblers can perform programmed tasks in seconds. The encyclopedia does not explain the combat effectiveness of this ability, but playthroughs demonstrate that the omni-tool generates a mine (possibly an EMP generator of some variant) that the squad member then throws at the enemy like a grenade. The third game takes this even one step further by letting them produce a Laser Blade / Power Fist on command for melee attacks. Oh - and they can run games as well.
 * Half-Life 2 series
 * Alyx Vance carries around an all-purpose electronic...thing that seems capable of overriding, reprogramming or destroying pretty much any electronic barrier that stands in your way. Alyx then uses a gun on humanoid adversaries. The player's near-multiversal-tool, the Gravity Gun, is useless on heavier objects and humanoid enemies.
 * The mod Empires features engineer classes with these kinds of tools. They do everything from constructing turrets to repairing personal armor to dismantling enemy buildings to reviving fallen troops (aka necromancy).
 * The multiplayer game Warhawk features a wrench that repairs any friendly or unoccupied vehicle or turret by whacking it repeatedly. However, it can be used to destroy enemy equipment or just smack someone upside the head for an instant kill.
 * Construction units and Commanders in Total Annihilation had nanolathes, which could create buildings and units, absorb terrain objects and wrecks for resources, repair damaged units, restore wrecked units and structures to full combat readiness, and even capture enemy units.
 * In Far Cry 2, any kind of damage to any vehicle (short of complete destruction, natch) can be fixed by taking a few moments to tighten a bolt somewhere under the hood with your ratchet of awesome.
 * Homeworld: The mysterious green beam, which fixes ships, is apparently the reverse operation of the mysterious red beam which gathers resources. In the sequel, harvesting is done by mechanical arms on the harvester, an apparent step back in technology. Probably taken from/inspired by Total Annihilation (see above), which predates Homeworld by a couple of years.
 * Dark Cloud: "Repair Powder," which takes this to a whole new level: merely sprinkling this miraculous powder on a weapon will instantaneously repair it.
 * Savage: There's no problem that can't be solved by hitting it with a sword.
 * Deus Ex is a rare first-person shooter that almost completely averts the trope. You have nano-lockpicks, which can reform themselves to, well, pick locks. But for electronic security, such as keypads or security cameras, you need to use a different device, called a multi-tool. The function of these tools is more magical than the lockpicks. Finally, to break things such as crates open, you need an object such as a crowbar, police baton, or sword, all of which are themselves usable as weapons. The sequel plays it straight, abolishing lockpicks, as all traditional locks have vanished and replaced with keypads.
 * In Sins of a Solar Empire, the construction ships can build any structure. With a blowtorch
 * Geneforge: Living tools in the series. Use them to pick locks, sabotage stuff, repair stuff, anything. Of course, since it's a bunch of tentacles strong enough to bend metal and fine enough to do delicate work, it should be pretty versatile.
 * The three factions from Supreme Commander have three different Magic Tools:
 * UEF: Similar to a laser printer, consists of blue beams buzzing around the structure/unit.
 * Cybran: Swarm of small drones, shoot red beams, similar to UEF's.
 * Aeon: Unit transformed from amorphous ball of silver sludge.
 * The first two are the same when building units, structures, repairing and reclaiming resources.
 * In Gadget Trial, Izen medics use a giant syringe to heal/repair all other E-series. Which means from other Izens (infantry units), to battleships and bombers.
 * Desert Strike features "Armor Repair" Toolboxes scattered about each level, pick one up and it inexplicably repairs your chopper to full strength.
 * In the Golden Eye 1997 game, a watch is used for everything, including a cutting torch, a deadly laser, to receive communications, the pause and inventory menu...

Web Comics

 * The proposed Utility Fog in Dresden Codak.

Web Original

 * Whateley Universe: At the Super Hero School Whateley Academy, Compiler has the power to control and animate nanites within five feet of herself. She has a nanotech Magic Tool that she even calls a 'sonic screwdriver'. We've seen it transform into a magic marker complete with working ink. It's nothing but nanites, so it doesn't work if it's not close to her.

Western Animation

 * Penny's "book" in Inspector Gadget seems to be a complete electronic warfare system packed into a notebook computer.
 * Leela's "thing on my wrist" in Futurama.
 * Kim Possible's "Kimmunicator" has whatever kind of Everything Sensor she might need, universal computer access, extensible robot arms for her Mission Control to help with and even the ability to fly back home if she loses it.

Real Life

 * Multitools. The name says it all.
 * Swiss army knives use this trope as a major selling point.
 * Modern smartphones: Your basic Internet-connected computer, GPS receiver, digital still/video camera, music player, alarm clock and pocket watch. Some of them even make telephone calls!
 * Well, yeah, that is kind of the point. How many people bought a shiny new iPhone to make calls?
 * Wait, you can make calls on an iPhone?