Differentiate your criminal malefactors!
You may not know it, but terms like 'bandits', 'outlaws', 'pillagers', 'highwaymen', and so on all mean different things. If your party is going up against violent robbers and criminals in your game, make sure you know the difference, because a freebooter isn't a pirate if they're from your kingdom, and a footpad shouldn't necessarily be treated as if they were an outlaw.
All kinds of criminal malefactors are more likely to be found where there is weak state administration, rough terrain, and recent or nearby war.
BRIGANDS
Brigands are highway robbers - people who steal from travellers on roads, usually by force and/or intimidation. They usually operate as a gang and are commonly deserted soldiers.
Footpads are brigands on foot.
Highwayman are brigands who are usually mounted and - being able to roam widely to find targets and escape consequences - less likely to be part of a gang. Carjackers are modern highwaymen who steal cars.
Expected TTRPG PC intervention: kill or drive off brigands in self-defence; round up and capture or kill brigands if approved by the authorities or in weakly governed/lawless areas; otherwise drag them to justice
PIRATES
Pirates are brigands of the seas - people with ships who steal from other people with ships, almost always by force and/or intimidation. Using a ship they can make off with substantially more cargo than a land brigand.
River pirates use, and target, boats rather than ships.
Expected TTRPG PC intervention: kill or drive off pirates in self-defence; hunt down and capture or kill pirates if approved by the authorities or on the open seas (depending on setting); otherwise drag them to justice
FREEBOOTERS
Freebooters or 'privateers' are people who pillage, plunder, raid, or capture the ships of other states, using their own ship - often a warship. Freebooters mostly attack merchant ships.
They are not technically pirates - they have been given license to act by their own state, either by blanket order, or by issuing something like a personal 'letter of marque' - an official commission authorising their actions. But another state's freebooters may be considered pirates and/or outlaws.
Corsairs are historically French freebooters.
Expected TTRPG PC intervention: kill or drive off freebooters in self-defence, and take their stuff; capturing them and dragging them to justice may be preferred in some settings
OUTLAWS
Outlaws are, literally, people who are officially outside the law. Outlawry is conferred as a criminal sentence or decree. An outlaw does not enjoy any of the legal protections of the law, including against killing. This opens outlaws up to mob justice, extrajudicial killing with impunity, and so on.
An outlaw might turn to brigandry, piracy, or marauding (if they weren't already).
In some contexts it might be not merely lawful but praiseworthy to kill an outlaw.
Outlawry is a form of unpersoning; in some contexts to give an outlaw any kind of support is illegal, akin to 'aiding and abetting'.
A desperado is a particularly bold or dangerous outlaw.
Expected TTRPG PC intervention: unlike with brigands or pirates, dealing with outlaws does not require - and usually cannot involve - any legal mechanisms. The unambiguously worst legal status has already been inflicted on them. The authorities are fine with a group of PCs doing anything to outlaws except tying them up and dumping them on the courthouse steps for 'justice'. There is no more justice to be done. This is something that can be hard for us modern people to understand: The law has no more official business with them.
BANDITS
The word 'bandit' is a little ambiguous, usually referring to a brigand but sometimes to an outlaw or a marauder.
MARAUDERS
A marauder is someone, usually an ex-soldier, who roves the countryside looting, plundering, pillaging, and sacking (related words which mean to unlawfully seize and/or destroy property). This is usually accomplished with or accompanied by violence, sometimes extreme forms like torture or terrorism. Marauders usually work in groups to accomplish this.
A marauder might also be called a plunderer or pillager.
Expected TTRPG PC intervention: kill or drive off marauders in self-defence; round up and capture or kill marauders if approved by the authorities or in weakly governed/lawless areas; otherwise drag them to justice
RAIDERS
Raiders are those from a culture/society/state in which raiding other cultures/societies/states is permissible, who do so. 'Raiding' here means travelling to a population centre to loot/plunder/pillage/sack as a marauder does. Raiding sometimes also has connotations of enslaving people.
Expected TTRPG PC intervention: raiders from other states usually don't enjoy legal protections; typically the expected thing is to kill them (reactively or proactively) in defence of the state and its people
THE MORE YOU KNOW
What does a lawful good paladin do with a brigand or pirate? Capture them to be tried. What does a lawful good paladin do with a raider? Dispense swift death. What does a lawful good paladin do with an outlaw? Well, now they have to decide what's 'good'.
