A name is a powerful thing, carrying weight and attribution. To be able to name someone is to apply things to them, to identify them. On the flip side, though, those who have no names are inexorably more powerful than those without them. When you don't have a name, you become much harder to track, to pin down — and if your enemies can't find you, they can't kill you.
It's rather fitting, then, that some of the most capable game characters have no names. Or, at the very least, they have names, but for whatever reason, no one ever seems to use them. It's a little strange sometimes, but again, being nameless is to be free of certain burdens.
10 The Traveler - Genshin Impact
Both the male and female player characters in Genshin Impact have canon names, Aether and Lumine respectively. If either of them ever tried to tell their numerous traveling companions about those names, though, nobody has listened. To everyone in Teyvat, they're just 'the Traveler.'
It may seem like a bit of a vague name to refer to someone as, but it does make sense. Aether and Lumine are pretty clearly not from Teyvat, both in terms of their general appearance and their abilities, so it's rather fitting to call them Travelers. It's certainly easier to say than "that blond(e) weirdo who can do elemental stuff without a Vision."
9 The Vault Hunters - Borderlands Series
For about as long as the legend of the Vaults has circulated across Pandora and beyond, there have been Vault Hunters. To call yourself a Vault Hunter publicly is to basically declare to the world "I carry a big gun around, and am unhinged enough to use it to look for something that might not even exist." That kind of says all it needs to right there.
This is probably why, at least while they're playable characters, all the Vault Hunters in the Borderlands games are only referred to as such. They all have names, and in Borderlands 3 in particular — where character dialogue is more plentiful — they'll happily offer them up. But when someone's making plans, and they need a knucklehead with a gun to help out, they don't need So-And-So from whatever planet, they need a Vault Hunter.
8 The Marine/Slayer - Doom Series
Long, long ago, the man who would eventually become the fearsome demigod known as the Doom Slayer was just a Marine stationed on Mars. Presumably, he had a name at some point, and he probably had friends or family who knew that name.
Unfortunately, temporal shenanigans are part and parcel of an extended stay in Hell and its adjacent realities. This means that anyone who ever knew that Marine's real name is probably long gone. Heck, even if they were still around, they probably wouldn't even think to attribute that name to a walking force of nature like the Slayer. It'd be like finding a nuclear warhead and naming it after your friend from grade school.
7 The Dragonborn - The Elder Scrolls V: Skyrim
While you can set your player character's name in Skyrim, most NPCs will refer to you as 'Dragonborn' in direct dialogue. The only exception to this is when you receive written correspondence, like a letter or a wanted poster. Otherwise, the fact that you're a Dragonborn kind of supersedes any other naming conventions.
In fairness, the Dragonborn is a big deal to the residents of Skyrim, and it's been a minute since one appeared. If a legendary hero was walking around in front of you, you'd probably want to remind yourself and everyone around you that, yes, it is actually the legendary Dragonborn.
6 The Courier - Fallout: New Vegas
In the modern Fallout games, your protagonist is usually given an unofficial moniker by the people of the Wasteland — something like 'the Lone Wanderer' or 'the Sole Survivor'. The protagonist of Fallout: New Vegas is the exception to this; they're just 'the Courier'. No fancy title, just a simple job description. They carry stuff from one place to another.
This may be another example of people simplifying names for the sake of convenience, though for those in the know — like Mr. House — it may run deeper than that. After all, the Courier is supposed to be the one carrying the Platinum Chip, so when you hear that the Courier is coming, you make sure to pay attention.
5 The G-Man - Half-Life Series
.jpg?q=50&fit=crop&w=740&dpr=1.5)
Here's an fun fact: while the mysterious 'G-Man' is one of the Half-Life series' most iconic characters, no one in the main story ever refers to him as such. Granted, this is probably because the only characters who are confirmed to know him are Gordon, who never talks, and Eli Vance, who's vague about him.
The only person to ever refer to the G-Man with that particular moniker is Adrian Shephard, protagonist of Half-Life: Opposing Force. Even then, it's only in the game's instructional manual. Given the G-Man's general appearance, including his bland suit and off-putting demeanor, it kind of makes sense to identify him as such.
4 The Arbiter - Halo Series
In his prime, the Sangheli formerly known as Thel 'Vadam was the highly decorated Supreme Commander of the Fleet of Particular Justice within the Covenant. When he messed up a mission and lost a Forerunner relic, though, he was swiftly branded incompetent and stripped of his title. In the place of both that title and his name, he was forced into the role of the Arbiter.
For the Sangheli in the Covenant, to be called the Arbiter is kind of like the ultimate backhanded compliment. The title used to be one of high honor, but after an Arbiter declared he didn't believe in the Covenant's mission, the High Prophets started using it to justify sending dishonored soldiers on dangerous, often impossible suicide missions. For the Arbiter we know in the Halo games, the title started as that same brand of shame, but through his heroic actions, it once again came to be known as a name of honor.
3 The Shifu - Live A Live
In the mountainous countryside of Imperial China, there is a humble home atop the peaks. In this home lives the lone Shifu of the Earthen Heart style of kung fu. While nobody in the surrounding towns knows much about the Shifu, they don't really need to. All that matters is that he's the Shifu, and that he is unquestionably the toughest guy around.
Interestingly, unlike every other protagonist in Live A Live, you can't change the Shifu's name — only the name of the martial art he practices and teaches to his disciples. Perhaps, to the Shifu, worldly things like names aren't especially important. All that matters is the art of polishing one's body, mind, and spirit to their utmost.
2 The Voodoo Lady - Monkey Island Series
In just about every entry in the Monkey Island series, hapless pirate Guybrush Threepwood has a run-in with the mysterious Voodoo Lady. The Voodoo Lady is the owner and proprietor of an apparent chain of voodoo and curio shops across the Caribbean, one which Guybrush always seems to inadvertently stumble into during his various adventures.
Guybrush actually asks the Voodoo Lady once if 'Voodoo Lady' is her real name. It isn't, obviously, but she ain't telling him what her real name is. After all, in the realm of voodoo — where you can kill someone just by making a doll that looks like them — a name is too dangerous a thing to be casually divulging.
1 The Mercs - Team Fortress 2
To defeat his brother in their endless feud over a pile of gravel, Redmond Mann hired a team of the nine greatest mercenaries in the world. Of course, he didn't expect his brother, Blutarch, to hire an inexplicably identical team, which made this whole process a tad confusing.
All nine of the Team Fortress 2 mercs have names and lives of their own, and some have been revealed in supplementary material such as comics and animations. In the game proper, though, all that matters is their job titles. The reason for this has never been given, but it's probably either a matter of simple professional detachment, or they're simply too absentminded to learn new names. Either is plausible, really.