Well, if the adventurers in question routinely interact with people with their weapons drawn, while having no legal backing or official standing, they’ll probably be regarded as dangerous bandits.
I have not seen many PCs do this, however. In modern settings, PCs who go armed have CCW in states which require it. Some are retired LEO with rights to carry derived from that. Others may be Reserve Sheriff’s Deputies, with departmentally issued or approved weapons. And they don’t draw their weapons unless the situation justifies it, legally and sensibly.
In campaigns set in historical eras or fantasy settings, PCs tend to act similarly. If they go armed, they have a legal right to do so, and will wear evidence of that fact. If knights or nobles, their arms will bear the heraldry of their station. If they are mercenaries, their band will be licensed and they wear surcoats, even uniforms, proclaiming their status as members.
As mercenaries, privateers, men-at-arms or whatever other form of intrepid adventurers they are, they will have the right to bear arms. Drawing those arms, let alone bringing them close to anyone, is something which they don’t necessarily do lightly, as that can cause people around them to flee, assuming that they are some kind of bandit or spree killer. It can also cause swordsmen with official standing to draw on them.
There was an incident when the PCs were visiting a foreign port and had not made any arrangements with local authorities or nobles. Bravos in the street at night, coming out of a wine shop, tried to threaten and bully them. When an NPC ally of the PCs reacted to crude sexual taunts with derision and a firm knee to the testicles, there might have been some hope of avoiding escalation, but swords were drawn.
In seconds, three wine-shop bravos were down and bleeding, because the PCs and their allies made their living fighting boarding actions against desperate pirates. They reacted with deadly violence, not showy performative fencing displays of young men pretending being dangerous. Two of the young men could be saved in the aftermath. One could not, he bled out. And happened to be the son of a local noble, doing what privileged young men often do.
The resulting court case required bribery to avoid the death penalty. They managed to get it down to exile and a hefty fine, restitution to the noble family. There is still some danger that the father or a brother will demand blood vengeance, but as the PCs now command a mercenary army and fleet of former pirates, now sworn to them as privateers, it is difficult for a foreign noble to lose a credible threat.
