One of our players highly recommends this series, but I never managed to get my hands on any full-length episodes. I finally got around to searching for some clips, and found this one particularly pertinent to the period in which our current trial world is set and explores one sort of encounter the party might face. Ignoring for a moment the ridiculous historical inaccuracy of the costumes, this scene is interesting because it provides some insight as to how two the interaction between two groups meeting for the first time might escalate into combat.
Synopsis: The captain of the guard at the shore of the Kingom of Northumbria (referring to himself anachronistically as the 'sheriff') rides up with his men to a party of very obvious Viking raiders to find out what they're doing there. He's the only one communicating with the Viking leader, Ragnar, and his side becomes increasingly tense while the Viking side becomes increasingly bloodthirsty, and eventually they clash.
First, it seems a rather blatant tension-building device to have Ragnar conversant in Aenglisc while the 'sherrif' doesn't seem to understand whatever North Germanic language the Vikings are meant to be speaking. The leader of a shoreline patrol group would likely have been chosen partly for his ability in one or more languages spoken by people likely to land at that shore, whereas a leader of Vikings should probably have been chosen more for his capacity to lead in battle than for his communication ability. Conveniently for our purposes, however, AD&D has a character's INT score tied to both strategic ability and number of languages in which he can communicate.
As the conversation opens, the captain asks if the Vikings are merchants. 'Yes, traders, yes!' Ragnar asserts. Sure. That's why we're armed to the teeth and have no visible merchandise of any kind. Some of the Vikings already have their hands on their weapons, and a particularly eager one nearby, called Rollo (apparently Ragnar's brother, according to Wikipedia), is growing increasingly suspicious of dialogue he can't understand. He soon insists that the sheriff's invitation is a trap.
The idea of the volatile band of ruffians being somewhat beyond their leader's control is probably realistic, although obviously exaggerated for effect here. The degree of hubris the vikings express, and their confidence in their fighting ability, seem far-fetched considering they've just spent weeks at sea and have no armour, while the Anglo-Saxons have some chain mail and helmets, freshly polished weapons, and two horses. Nonetheless, the Vikings are bloodthirsty and bent on doing what they came to do, namely kill people and take their stuff.
One Anglo-Saxon soldier's suggestion to 'offer them money to go away' is a transparent reference to the policy of later Anglo-Saxon kings of bribing the Vikings not to invade--in retrospect, a suicidally stupid tactic, but as Machiavelli wasn't yet around to offer sagacious foreign policy advice, they're forgiven.
As a peace offering, the sheriff gives Rollo an amulet he's wearing, which inspires another Viking to step forward and snatch a cross from another Anglo-Saxon's neck, which act of agression immediately causes the other Anglo-Saxons to draw their swords. As the sheriff tries to tell them to stand down, he is struck down by Rollo's battle axe. All the Vikings, including Ragnar, rush forward and slay nearly all the Anglo-Saxons, leaving only one to escape on horseback.
I've had parties behave in completely lawless ways before, usually with things going significantly less well for them than it went for the Vikings. Generally, local law enforcement has showed up in superior numbers well prepared for a fight, and the PCs have done things ranging from taunting them verbally (when they spoke mutually intelligible languages) to brandishing swords or attacking them outright (when no verbal communication was possible). This has resulted in the untimely deaths of more than one treasured character, and is a strategy generally hazardous to PC health unless, as here, they clearly possess the superior fighting power, and are prepared to meet the consequences when, as here, a survivor among their newly-made enemies has retreated to alert the country of the party's hostile presence.