And then there are some quests that require you to kill a specific target stealthily.
Enter Assassination Sidequest, a type of sidequest that requires you to kill someone without alerting the others. In an Assassination Sidequest, your goal is to act like an assassin, avoid unneeded attentions, take down the specific target with minimal collateral damages and evacuate before a security guard can discover you.
Due to the nature of avoiding attention, many quests involving assassination often overlap with Stealth-Based Mission, since you often need to infiltrate into the area where you can take out your target. It may overlap with Sniping Mission if you need to snipe your target from afar, or Stalking Mission if you need to follow your mark until they reached a designated location.
Compare Mass Monster Slaughter Sidequest, which is about slaying a set amount of monsters, 20 Bear Asses, a Fetch Quest where you have to kill a certain number of enemies and collect an item they drop, and Stealth-Based Mission, a type of mission that requires you to sneak around. See also Stealth-Based Game, where assassination and stealth are the whole point of the game, Professional Killer when the Player Character is an assassin, and Murder, Inc. for an assassin guild. If it's a sequence of quests it may fall under Gotta Kill Them All.
- Honkai Impact 3rd: In the Sakura Samsara game mode (which takes place in an "open world" system), one of the tasks you can take is to stealthily kill a number of roaming monsters. By activating "stealth mode", the monsters are less likely to be aware of your presence, and you also get the Back Stab mechanic which can kill said monsters in one hit.
- Syphon Filter: The Omega Strain has a bonus mission of this type where your character has a sniper rifle loaded with only one bullet to carry out his assassination, and must stealth melee kill any guards in the way, making sure their bodies are hidden.
- Age of Empires III has a mission in the "Blood" campaign where Morgan and Lizzie have to take control of gold ships. One of the side missions is to assassinate spanish conquistador Francisco Delgado.
- in Demon's Souls, Mephistopheles would ask you to assassinate the inhabitants of Nexus. Should you complete all of her tasks, she immediately turns against you.
- Dark Souls:
- In Dark Souls II, Royal Sorcerer Navlaan (or rather, the evil spirit possessing him) asks you to assassinate several NPCs and bring back a specific belonging of theirs as proof of their death. Since he's locked up behind a magic barrier and can't exactly go and confirm your kills himself, you can fool him by obtaining the items non-lethally and complete the quest that way.
- Downplayed in Dark Souls III, there is only one assassination sidequest. Yuria of Londor would ask you to kill Orbeck of Vinhelm, fearing that he would hinder your path to becoming the Lord of Hollows. Like in the previous game, you can complete this quest without killing him. If you find all of the sorcery scrolls in the game and give them to him, and buy out his entire stock of spells, he will leave Firelink Shrine and get killed all on his own. After defeating the Twin Princes, you can find his corpse in the Grand Archives containing his ashes, which you can present to Yuria as proof of his death. True, Orbeck still had to die, but at least you didn't kill him!
- Dragon Age: Origins has the Trial of Crows, an assassination sidequest series offered by Ignacio in Denerim to get rid of several targets. Notable that he is offering this to the Warden, who was targeted by the Crows but managed to survive an attempt on their lives.
- The Elder Scrolls:
- In Morrowind, you can join the Morag Tong, a legal Dunmeri organization of "Professional Killer" style assassins. Given the organization's legal nature, stealth killing isn't necessary. In fact, according to the organization's rules, an assassin is expected to turn themself in to present their "Honorable Writ of Execution" in order to ensure make sure the killing remains above board.
- In Oblivion and Skyrim, the Dark Brotherhood offers you a series of sidequests that involves killing specific people. It isn't necessary to kill stealthily, but in order to avoid incurring a bounty, it is recommended to eliminate your target through stealth. In some cases, bonuses are offered should your remain undetected and/or kill your target in a specific fashion. (Such as making it look an accident.)
- In Fallout: New Vegas, choosing to side with the Legion opens up the "Arizona Killer" quest. In it, you are tasked with assassinating NCR president Kimball at the Hoover Dam while he gives a speech to the troops. You are given NCR armor as a disguise, but the area is full of NCR Rangers who can see through disguises if you get too close, so stealth is a must. You have no fewer than 13 different options for the assassination, ranging from sneaking explosives aboard his Vertibird, to planting explosives on a soldier receiving a medal, to sniping him, to flat out running up and killing him in close quarters.
- In Fallout 4, Diamond City offers bounties via the "Most Wanted" sign. While each of the bounties states that you need to clear out all of the hostiles in a particular area, in practice, you only need to kill the one enemy in the area with a quest marker. Using stealth, you can sneak into the location and only kill the one needed to satisfy the quest. The "Silver Shroud" quest also requires you to build notoriety by taking out several Raider bosses — one of which was holding a contract of their own to complete against an apparently innocent squatter. You can either collect the bounty on this one by killing the woman, or toss the contract and spare her life.
- Grand Theft Auto V: Lester offers Franklin several missions to assassinate people connected to large corporations in order to manipulate the stock market. Savvy players will also take advantage. Although, due to lack of short selling, you need to know who the targets' competitors are to maximize profits. Only the first assassination is required to advance the plot.
- Far Cry 4 has a number of side quests in which Royal Army officers need to be killed stealthily, sometimes with an added twist such as having to use a certain weapon type, follow the officer to a certain location first, or retrieve documents from the officer's corpse.
- In the Saints Row series, you can find a list of assassination contracts requesting you to eliminate specific people, and the reward ranges from money to new costumes. In order to make the target show up, sometimes you need to do many ridiculous things following the instruction, ranging from taunting pedestrians to calling your mark to meet you on an island, something an assassin normally wouldn't do.
- Whateley Universe: Game in a Story: In Good And Evil Online, Whisper gets a sidequest to kill the leader of the neutral faction.