Adventurers

Adventurers are a special sort of folk. While they come from myriad diverse backgrounds, they all exhibit a mad sort of bravery that goes beyond what most people can truly grasp. Some take on the mantle in service to their god or some other higher power. Some find themselves cast adrift from society, driven by deep personal trauma. Some seek glory. Some are simply in it for the money. But who else would challenge a dragon in its lair? Venture into a cavern to confront the nightmare dwelling within? One and all, they are the stuff of legends. Not all survive to see those legends written - many don't even survive long enough to inspire those legends in the first place. But all are worthy of the title, regardless.

Culture

Major language groups and dialects

Adventurers come from a diverse array of backgrounds, and often speak a wide array of languages, including esoteric languages rarely encountered in the present day. Additionally, nearly all will speak the local language of the fieldfolk, as well as the trader's tongue - a typical group will use one or both of these languages to communicate with one another, as well as for negotiating with those seeking their services.

Shared customary codes and values

Adventurers tend to be the guardians of the common people. Most will intercede to protect anyone who doesn't seem to be able to protect themselves, though, if time permits, some may complain dramatically along the way.
However, they are not entirely selfless (and some are quite far from it). Their services are in high demand, and they well know it. They demand a far higher price than a simple mercenary, but a mercenary might well look at the job they are asked to do and then take the money and run. Most adventurers won't do this - it is considered the very peak of bad form. While their demands may be high, it is worth noting that any attempting to hire them would be ill advised to offer more than they can actually pay - adventurers have been known to get creative with how they pay back those who would attempt to scam them.
Adventurers tend to see other groups as friendly competitors rather than rivals or enemies. Few will take a job intended to interdict another group's progress - and they may well take it upon themselves to warn the other group. They also tend not to appreciate contract poaching - if one group is hired to do a task, that task is theirs for the doing. However, until the deal is made, offering services for a smaller reward is fair game. (Though it can be unwise to hire a party willing to work for too little pay - this may be a sign of an inexperienced group who might be critically underestimating the dangers ahead of them.)