Protection Mission

A cross between Escort Mission and Hold the Line where you're staying in one place and protect a stationary object or NPC while enemies pour in and attack your charge. Usually, you either have to protect them for a specific period of time, or just kill all the enemies.

It doesn't have to be one object. Sometimes it's an array of objects, and if a certain number are destroyed, you fail.

Tend to be easier than classic Escort Missions, since you do not have to worry about the idiot escortees blundering into danger. And apparently trying to make you think The Computer Is a Cheating Bastard or A.I. Is a Crapshoot.

See also Tower Defense games, where you're generally tasked to protect a stationary object.

Tabletop Games

 * Basic Dungeons & Dragons adventure IM1 The Immortal Storm. A PC must act as a defender against the attacks of Spectral Hounds as his Hierarch uses an artifact to stop the title storm.

Video Games

 * Prototype has the deployed toxin pumper for the protecting.
 * The reinforced glass barrier keeping Ragland safe as well.
 * Interesting variant would be the collection of biomatter outside of a hive that the military shows up to destroy. As long as you collect sufficient matter quickly enough, you may not even have to touch the military due the pair of hunters defending the hive against both them and you.
 * The sequel Prototype 2 has another one where you will need to defend a downed helicopter with a plot-important person inside.
 * Near the end of Half Life, where you're about to teleport into the Another Dimension, you have to prevent aliens from killing a scientist who's busy setting up the teleporter until he finishes his job.
 * Pops up a few times in the tactical strategy Odium. Four times you have to kill the enemies before they kill a stationary NPC (who, of course, just stands there while enemies attack him). Once you have to protect some security monitors (why do the mindless monsters have an apparent temporary grudge against them is unexplained.)
 * Zombie Horde 2. Every once in a while you have to protect a box from zombie attacks.
 * Battle City series. Player has to protect the bird located in the bottom middle of the field from enemy tanks while staying alive as well.
 * A (rather frustratingly difficult, at least compared to the rest of the game) battle towards the end of Sakura Wars V: So Long, My Love has the party of PCs protecting various vital parts of an airship they're on.
 * The classic arcade game Missile Command. "Defend Your Cities!"
 * Final Fantasy VI has a few parts like this. Once near the start of the game where you have to protect an unconscious Terra from Imperial troops, and again with a similar mechanic later on when you protect a frozen Esper from more Imperial troops.
 * Majoras Mask requires you to protect milk jugs on the back of a wagon from Romani Ranch.
 * The penultimate battle in God of War, where Kratos (you) has to protect the memory of his wife and child against hordes of evil versions of himself. It Makes Sense in Context, really!
 * World of Warcraft has several of these. One where you have to protect a crystal from several waves of enemies, and another where you have to protect the Hourglass of Eternity, with some help from your future self. Later, you get to do it again, this time as the future self, helping your past self.
 * In WolfQuest, one of the missions is to protect your pups from the hungry coyotes and bears. It gets more difficult when you must move them to the summer hunting grounds and an eagle decides they look tasty.
 * Tower Defense games are pretty much entirely focused on this idea.
 * In StarCraft, a few of the Zerg missions require you to protect a mysterious Chrysalis. Eventually it hatches, revealing . Only some of the missions technically count, as in the first few, it's small enough to be carried around by a Drone.
 * In the sequel, you have to protect a laser drill while the Protoss send waves of troops against you. Fortunately, you get siege tanks in this mission, and you can aim the drill automatically, making short work of any enemy unit that's not in the fog of war.
 * Ariel Hanson's missions involve you protecting a fleet of refugees from a variety of threats as they seek out a new homeworld. These threats range from infested zombie-like terrans to full-on zerg assaults to a purification squad helmed by Executor Selendis.
 * Warcraft continues the long, glorious tradition. The final mission of Warcraft III is probably the most prominent: the object to be protected is the World Tree. Except you're not just protecting it—you're protecting it while it gets rigged into a gigantic magical bomb meant for an archdemon.
 * Several missions in Naruto: Uzumaki Chronicles are like this.
 * A particularly frustrating mission of Tribes: Vengeance is centered around Victoria protecting Daniel from onrushing Blood Eagles while he extracts the data from an enemy computer. The main problem is that the location is very poorly suited for prolonged defense, your resources are painfully limited, and there is no backup whatsoever (except a few automatic turrets).
 * In both of the Modern Warfare games, there is a mission where the player has to defend a stationary objective. In the first one, the player's Marine squad has to protect a M1 Abrams tank that has been disabled. If the enemy get close enough, they'll use satchel charges to blow it up. In the second game, the player's squad has to defend a portable hard drive as it downloads the contents of a terrorist leader's computers while dozens of mercenaries rappel in by helicopter to try and destroy it.
 * Occurs in Golden Eye Wii when you must protect Natalya from enemy gunfire while she tries to stop the Goldeneye satellite.
 * Same with Golden Eye 1997 64, except it was much more frustrating.
 * In Famous has a particularly harrowing mission involving protecting a medical crate. If you've started down the Evil path, the waves of baddies can be subdued with a little mass damage... but if you have Good Cole's abilities... well, be ready to restart the mission a couple times until you manage to take out the gunner trucks and rocket launchers before they make your crate go kablooey.
 * Protecting Hawk while he disarms a nuclear bomb in Soldier of Fortune.
 * A number of quests in Dungeons and Dragons Online are this, including two of the quests of Korthos Island.
 * Several times in Conduit 2, protagonist Michael Ford must protect the Free Drudge during the campaign.
 * Fable II has quite a few of these, one where you have to protect Garth whilst he activates a gate.
 * Resident Evil 5 has one of the BSAA members, Josh, inputing a code in order to turn on the power for the elevator for him, Chris and Sheva to escape on. You also have to do it again. He even remarks how much of a pain it is for you.
 * The entire point of Sector Z in Star Fox 64 is that the Great Fox just stops in the middle of nowhere while the enemy fires 6 large missiles in 1-2-3 sequences at it. Thankfully, you have plenty of time to destroy each missile, and they always come from the same direction. This mission is also paid homage to in Level 8 of Star Fox Assault, when you have to protect the Orbital Gate from a lot more missiles coming from all different directions.
 * Numerous examples from Fire Emblem. Most frequently, it's an incapacitated "Ally" NPC, or some other figure such as Royals who aren't as talented as yours at fighting. While many missions are "Seize the throne", there are a few where it's inverted which would also fit this trope. Some of them are also Luck Based Missions, since if you are unlucky, the character you are supposed to protect can get killed before you even have a chance to reach him/her.
 * In Solatorobo, during Red's Journey to the Center of the Mind, the software begins by creating a warmup for him from his memories. He winds up defending Elh from a bunch of bugs, seeing as that's what he considered the most laughably easy thing to come up with. A later simulation reuses the "don't let the bugs near Elh" objective, but that one was
 * "You must save the totem, Turok!"
 * At the climax of Jade Empire, Silk Fox and Dawn Star (you control one) are defending a bridge while Kang the Mad sets up explosives.
 * Tron 2.0 has several, mostly in terms of guarding the AI Ma3a who is carrying the algorithms needed to run the digitizing laser (Jet's ticket back to analog). One of them is sniping rival security Programs from a tower, another is fending off Thorne and his horde of virus-inflected Programs in a Bar Brawl.
 * In Battlestar Galactica Online, you can call in mining ships to handle resource-bearing planetoids. The payoff from these is greater than spending an equal amount of time doing normal Asteroid Mining. However, the game spawns mooks to go after the mining ships, as well as creating an indicator on the sector map that may attract enemy players. Of course, you can invert this by going out and hunting enemy mining ships.
 * The second of the mid-game missions in Mega Man Zero 2 contains a segment toward the end where Zero must protect Ciel as she disarms a bomb, which takes 90 seconds. The enemies coming after you two are quite weak, but there are a lot of them.
 * City of Heroes had several of these, most notably the capstone of a Croatoa-based story arc where you had to find and lead several mystics to a stone circle, and then defend the circle from multiple waves of Red Caps while they completed a ritual.
 * City of Heroes had several of these, most notably the capstone of a Croatoa-based story arc where you had to find and lead several mystics to a stone circle, and then defend the circle from multiple waves of Red Caps while they completed a ritual.