A Non-Player Character who sticks with the Player Character throughout the game and usually has complementary skills (e.g. if you handle all the fighting, they may be a Utility Party Member) and a contrasting personality to the player character.
You usually cannot control them directly, but they are nevertheless the key to beating the game, as you either need their skills to fix Broken Bridges of all kinds or can call on them for Combination Attacks to bring down powerful bosses. When you have to defend them, the entire game can turn into a continuous Escort Mission; when given Gameplay Ally Immortality, on the other hand, they often seem to be escorting you.
Their role in the story can fall anywhere from Plucky Comic Relief Sidekick and Exposition Fairy, through Deuteragonist, all the way to relegating the player to Supporting Protagonist. Regardless, they often receive the most Character Development in the game and tend to facilitate the same in the player character via Dialog During Gameplay and other interactions. They also tend to be taken away from you at some point in the game—usually temporarily, in order for you to better appreciate their presence and help. Ultimately, they commonly end up on the receiving end of the Video Game Caring Potential.
RPGs often (but not always) allow you to recruit an entire Player Party of AI companions and to control them directly when needed (they also often provide you with unique sidequests); in other genres, you can usually (but not always) only have up to one at any time. In games with Co-Op Multiplayer, the second player may be allowed to take over the AI companion's controls—or the AI companion may be just a stand-in dummy for another player.
Super Trope to Manual Leader, AI Party (found in many RPGs), Platforming Pocket Pal (in Platformer games) and Assist Character (found mainly in Fighting Games). See Companion Cube for when the "companion" is an inanimate object (and hence has little AI) and Attack Drone for when the AI ally lacks personality and only has combat functions.
- Another Code: D in the first game and Matt in the second. They provide either backstory on your location or help with a puzzle or two.
- Towards the end of Hotel Dusk: Room 215 and Last Window, Kyle is joined for part of it by either Louie or Tony, who help to solve the various puzzles that keep you from getting to the end.
- Elika in Prince of Persia (2008) handles all things magical for you (magical attacks, magical healing of the land, magical rescues), while you, as the Prince, handle the physical fighting.
- Pey'j and Double-H accompany Jade at different points in Beyond Good & Evil. Unlike most examples, it's them who handle the heavy fighting, since Jade is a Guile Heroine and a Fragile Speedster, at best.
- Enslaved: Odyssey to the West features the Wrench Wench Trip, who complements Monkey's combat skills with technical expertise, and has to be protected during combat. They are also joined by Trip's friend Pigsy in some portions of the game.
- Miles "Tails" Prower to Sonic in Sonic the Hedgehog 2.
- Yamato the dog to Joe Musashi in Shadow Dancer.
- Several in the Zelda series, all towards Link: Navi in Ocarina of Time, Tatl in Majora's Mask, the King of Red Lions in Wind Waker, Ezlo in The Minish Cap, Midna in Twilight Princess, Ciela in Phantom Hourglass, Zelda in Spirit Tracks, and Fi in Skyward Sword.
- Drakan contains one of the rare examples of a non-human Non-Player Companion who is actually much more powerful than the Player Character: Arokh is an ancient dragon who accompanies the Action Girl Rynn on adventures. However, he is too large to squeeze into most dungeons, so Rynn has to clear them out on her on. Still, his help is invaluable for defeating outdoors enemies and pretty much the only way to defeat other dragons.
- Issun from Ōkami. Mostly, he acts as your voice and Plucky Comic Relief, but you can also get him to steal stuff off of enemies after gaining a certain ability.
- Planetfall has one of the earliest examples in Floyd the robot. Once you find and activate him, he follows you around, mostly making jokes but sometimes giving hints or solving puzzles as you direct him to.
- Wheatley takes this role at several points during the first half of Portal 2, and GLaDOS, in the form of a potato battery takes this place for almost all of the second half.
- Elizabeth in BioShock Infinite can open tears in the reality, keeps you (as Booker) supplied with ammo, health, and salts, and provides emergency resuscitation if you die. Oh, and she is the bona fide Deuteragonist of the game.
- Alyx Vance starts off as an occasional ally in Half-Life 2 but grows more and more into the role of consistent companion in Episode 1 and particularly 2.
- Call of Juarez: Bound in Blood plays with this trope by allowing you to choose whether to play as Thomas or Ray before each level, while the other brother is controlled by the AI. Both are equally important to the plot. Call of Juarez: The Cartel does the same thing but with three protagonists: you play as one of them, while the other two support you.
- Daikatana has two computer-controlled sidekicks, and they both suffer from the same horrible AI, made even worse by the fact that they have to survive or the level is failed.
- Star Wars: Republic Commando has not one, but three stable AI companions, each with a unique specialization (demolitions, sniper, and hacker).
- Similarly, Spec Ops: The Line has two AI companions following the player: Adams, specializing in heavy weaponry, and Lugo, a marksman.
- In Metal Gear Solid V: The Phantom Pain, Snake can enlist the aid of one of four "Buddies" who provide aid in his missions: D-Horse, a horse that Snake can ride on to travel quickly and stealthily; D-Dog, a wolfdog who can sniff out points of interest as well as run interference with enemies; Quiet, a sharpshooter Snake bested in a Sniper Duel who can provide reconnaissance and fire support; and D-Walker, a customizable Mini-Mecha that can be outfitted with various weapons and gadgets for a wide variety of situations.
- The various Wingmen in the Ace Combat series:
- Ace Combat 5: The Unsung War had four controllable wingmen (Edge, Chopper, Grimm, and Swordsman), though only up to three flew with you at any time.
- Pixy in Ace Combat Zero: The Belkan War is a wingman, a bona fide deuteragonist, and the Final Boss of the game. You also get a second wingman late in the game.
- Shamrock in Ace Combat 6: Fires of Liberation.
- Guts in Ace Combat: Assault Horizon is a true AI companion, while the Warwolf 3 and 4 are nameless Attack Drone stand-ins for other players who can join in the co-op mode.
- Tachyon: The Fringe allows you to hire a wingman who will follow you when you go out on missions. They each have their own dialogues, personalities, and stats and can suffer Character Death (apart from the robots, who are replaceable).
- Diablo II introduced the henchmen system, which allows you to hire a companion in all but one towns, though only one can follow you at any time. The companion can Level Up and be equipped with better gear, but does not replace the Player Party, which consists of other players' characters online. Diablo III refines this system, giving your followers (of which there are three options) personalities, customizable skills, and a unique type of gear for each follower that only they can use.
- Star Wars: The Old Republic has five unique companions in each class-specific storyline. Although they are discovered and recruited akin to a Player Party in single-player games, you can only bring one along at any time. Gameplay-wise, the companions serve to balance out the player character's combat specializations (e.g. they can be a tank to your DPS/healing), but they each also have a personal Sidequest Sidestory, unlocked by raising their Relationship Values: although for most, it is just a series of dialogues on your ship, the first companion each class recruits has an actual chain of short side missions you have to take them on, scattered across the galaxy.
- Similarly, in Fallout 3, Fallout: New Vegas, and Fallout 4, you can recruit several AI companions but can only bring one with you, while the rest wait for you at the hub locations. In New Vegas, you can have a "pet" follower (a robotic dog or an eyebot) in addition to a humanoid follower.
- The Elder Scrolls:
- Morrowind has NPC followers on multiple quests. You can give them orders to "Wait Here" or "Follow Me". Arming and armoring them beyond their default equipment isn't possible (save for using the Master Console on PC). The Tribunal expansion adds a mercenary that you can hire in Mournhold. He can be hired at any time and has an accessible inventory, so you can outfit him as you see fit. As is the case for every other NPC in the game, they can be killed. If they are related to a quest, this typically means failing that quest.
- Oblivion has NPC followers mostly in quests, though reaching the highest rank in the various Guilds/Factions usually grants you access to at least one follower available any time (in the case of the Arena, it's The Adoring Fan). They have a strong tendency to be Leeroy Jenkinses, but quite frankly the biggest hazard to their health is you since they love to run directly between you and the enemy. In an improvement since Morrowind, most of the quest-related followers are marked as "essential", so they can only be "knocked out", not killed. (There are exceptions where ensuring the character's survival is specifically part of the quest.)
- For Skyrim, Bethesda borrowed some ideas from the aforementioned The Elder Scrolls Fallout sister-series. Throughout the game, the player has the option of inviting certain NPCs to travel with them, after paying said follower (in the case of mercenaries) or by befriending the follower, which typically involves completing a quest for them or being a member of the same faction. They can carry the player's gear and will travel with them, following their lead (if the player sneaks, they'll sneak as well), and they can be given commands such as to wait or to pick something up. The NPC's personality will determine how they react to some things—for example, if the NPC has a high morality level, if the player tells them to attack someone they'll refuse, or if they see the player commit murder they'll turn on them. The player can only have one follower at a time, though some quests will have another person travel with them temporarily without all the regular follower options. In addition to a human follower, they can also have a creature follower at the same time: they can get a dog or buy an armored troll.
- In the original campaign of Neverwinter Nights 1, you can hire a companion from a selection representing every base class in the game. In fact, it can be advantageous to hire them all in turn, if you can spare the gold, since each one has a quest for a Plot Token which will earn you a useful magic item if you find the item and give it to your companion. You can only have one companion at a time but you can re-hire a former companion for no further cost.
- Neverwinter Nights 2 has a standard Player Party, but the second expansion Storm of Zehir allows you to add "cohorts" to the Featureless Protagonist party you built during character creation. The cohorts are all unique and range from a hammy druid with a deinonychus companion to a batshit insane Bare-Fisted Monk who never stops laughing.
- Rui in Pokémon Colosseum, who tags along with Wes to alert him to Shadow Pokemon.
- Trode and Medea in Dragon Quest VIII accompany the team for essentially the whole game, despite being non-combatants. Medea is cursed into the form of a horse and thus pulls the party's item-storing wagon, while Trode mans the Alchemy Pot and constantly pops up in dialogue scenes (to Yangus's eternal surprise.)
- The Supporter Class in the RPG-Mechanics Verse that is Is It Wrong to Try to Pick Up Girls in a Dungeon? is modeled after this kind of characters in old-school RPGs. For example, Lilly practically acts as Bell's Human Pack Mule, although she does have an Automatic Crossbow she can use if the need arises.
- Betrayal at House on the Hill has a few who can be triggered via omen cards, namely a girl, a madman, a stray dog, and a stray cat (in the expansion pack). Their utility depends on whether they're involved with the Haunt or not.
- Dungeons & Dragons. Apart from companions, allies and cohorts the players can gain via roleplaying, various characters can get non-player companions as part of their abilities.
- In early editions, players of a certain level would attract followers, including a guild of thieves or a keep of soldiers.
- Arcane spellcasters can gain a familiar.
- Paladins can gain a steed.
- Druids and rangers can gain animal companions.
- Taking the Leadership feat allows any character class to gain a companion.
- Pathfinder: On top of all the standard 3.5 examples, Pathfinder added the Summoner class, which gains an eidolon creature that levels up with the player character.