After a while of playing Rust, you will learn that you get to meet different types of people who can be broadly classified as follow. This guide is pretty misleading however, and conflates personality types with clothing, and refers to features no longer in the game (M4s, Kevlar). It was clearly written with legacy in mind and is thus YEARS out of date in places. Additionally, there's not much difference between "Griefers" and "Trolls" (Griefing being a form of trolling, and both being able to be performed by players of any sort of level). Some stuff is just nonsense "Raiders look like Bandits", which was clearly written by someone who wasn't very experienced with the game. Anyone who's "kitted out" is potentially expecting trouble, trying to intellectualise it is foolish. Any time someone kits up, they're risking a lot, so they obviously KOS more, and they're usually after something in particular.
"Neutrals" is just garbage and needs deleting. The author has mixed up the tech tree with behaviour. If someone isn't fucking with people, that doesn't mean their gear will always be inferior, and if you're busy trying to work out by comparing metal plates to other armours what someone's personality is, you've made a series of terrible mistakes.
The Troll
Trolls usually consist of seemingly 8-12 year old children who come charging at you with rocks and yelling racial slurs. Don't bother talking to them or befriending them. Just kill them on sight. This also includes noobs and idiots who crawl around your base trying to look funny. These guys aren't serious about playing Rust and are simply here to make other's experience miserable and to get attention.
How they communicate: Trolls are just mental. You can barely hold a steady conversation with them. They're not interested in talking to you anyway. Everything you say will be used against you, the more you talk to them, the worse they get as they feel approved by your response.
Appearance: Trolls are usually naked and don't have much tech on them (aside from the pickaxe they probably picked up from a crate nearby)
The KoS (Kill on Sight) guys
These guys are absolute assholes and are usually found in high-population servers. They are extremely territorial, relentless and usually associated with a clan. Don't bother approaching them with friendly intentions, because they're going to kill you on sight, no matter what; but they assume it's for the better. KoS guys are usually cautious and believe in exerting a certain amount of power over their fellow Rusters. The only way to get friendly with them is to contact them remotely through Chat or Steam.
KoS guys are usually quite experienced on Rust and don't stand to gain from any new tech that you might've acquired. But these experienced Rusters sometimes, have a weakness for animal fat and Explosive Charges. So offer them that and perhaps you can expect them to give you your stuff back the next time they KoS you.
How they communicate: You'll often see them bragging about killing someone on public chat. They usually sound a bit condescending towards inexperienced players.
Appearance: KoS guys usually wander about in Leather Gear, gathering resources. They don't want to be bothered, so leave them alone. They're probably gathering all that wood for building a new skyscraper.
Bandits
Bandits usually hang out in squads of 2 or more Rusters, Probably the most Common of the Rusters and, usually armed to the teeth with Kevlar Armor (black), M4 or Bolt Action Rifles. You'd barely ever see their chat messages in the log. These guys are deadly, and they often turn out to be extremely experienced Rusters whose sole purpose is to make other players rage-quit. If you see more than one player in Kevlar in a distance, just stop what you're doing and run the other way. You couldn't possibly stand a chance against them, unless you have an army of your own. These people stop at nothing, when it comes to raiding or robbing other players of their stuff.
How they communicate: Bandits are usually smart and mature, although they don't talk much on public chat.
Appearance: Nearly Always kitted with metal facemask/chestplate, assault rifles, bolt actions, high tier underclothing and usually brings alot of medical items for field-use.
Raiders
Raiders look like Bandits, except, they're probably on a mission to raid a specific base. Raiders are a bit more subtle in their approach and usually take hidden paths to their targets, preferably at night. Raiders are stealthier because they are carrying Explosive Charges on their way to the targets and returning with precious cargo. If you see a Raider, just hide. If a Raider is attacking a base next to you, simply disarm yourself and beg for your life and they'd usually leave you alone with a warning.
CAUTION: Never offer any help or try to assist raiders, even if they are raiding someone you hate because a) You'll never get a cut of the pie and b) They feel threatened. This includes raiders with whom you were friendly before.
How they communicate: Raiders would be stupid to communicate their plans on public chat. However when you do meet a raider at work, he/she will warn you not to get involved. Some of them can be rude, directly asking you to F-off. Others are less subtle and kill you on sight.
Appearance: Same as Bandits, but also carry some sort of demolition tool (C4, Rocket launcher, Grenades, Explosive bullets)
Friendly Noobs
These guys are usually unarmed, naked and often chased by wolves. They beg you not to kill them, even if you do so much as approach them with a hatchet. You know that these guys have good intentions, which is to play like anyone else. All they want to do is work hard, gather resources, acquire tech and build great things. Friendly noobs aren't really interested in killing other players, so you can be pretty sure, they will ally with you in the beginning and help you get on your feet.
How they communicate: Friendly noobs usually know their place and try to be as polite as possible. They are usually articulate and often ask questions.
Appearance: Naked or low level mismatched pieces of armor, carrying a bow at best. Not very experienced in close combat situations.
The Griefer
The infamous griefer, comes in all stripes and colors but it's not that difficult to determine if he/she will end up becoming one. Griefers do all sorts of things and can be mistaken for any one of the above 6. Plus, they exploit the game mechanics to simply give you more pain. For example, some griefers are extremely friendly and loyal at first but later on, you might suddenly find your base blocked off with walls and doors put down by these sadists. At other times, these griefers have you work hard to gather resources, then rob you when your back is turned. Griefers are simply cruel sadistic monsters. Deal with them as you please.
How they communicate: Griefers often consist of younger players and teens who don't communicate very well. They aren't very articulate in speech and often use very few words to communicate. However, they'd pretend to follow every order you give them, almost appearing to you like your slave or a servant.
Appearance: Nothing specific.
The Neutral
Neutrals are semi-experienced people with usually low to mid level armor and some basic guns (for example: a waterpipe shotgun or a revolver) and will usually try to find out if someone is friendly before attacking. Depending on what they or you have, they may either run from you, or approach you and perhaps give you some stuff.
How they communicate: Neutrals often consist of young to middle-age players who haven't fully learned what Rust exactly is yet. They can communicate decently and they might help you. Be careful however, they might attack if they feel threatened or Neutrals might be griefers in disguise!
Appearance: Burlap cloths, but they might have a piece of advanced armor.These personality "types" of Rusters may not be entirely accurate and is definitely not exhaustive. Besides, people's loyalties change depending on circumstances. This article is intended to help you only in the initial stages of interaction with a fellow Ruster.
The Hero
The hero(s) are semi-very experienced players. It is a rare occurring event of a friendly action from another player, the 'Hero' usually helps fending off mid-to-high geared players away from low-to-mid geared players, not a lot of heroes appear, because most of the time after they do their heroic actions, the hero is often killed by the player(s) they rescued, so if you see one or more of them helping you, go give them a friendly pat on the back or share a bit of your resources.
How they communicate: A Lot of heroes don't really talk, and are more like make-do when it comes to defending the weak to give them a chance.
Appearance: Usually comes in mid-to-high tier gear, but can be found in a lot of varities.