Rangers of the North

Generally speaking, rangers have been watered down and removed from their roots over the years. In 1st Edition, the class was very obviously based on Aragorn (particularly the otherwise out-of-place ability to use scrying devices), and therefore had a nice selection of magical abilities at higher levels that would otherwise be out-of-place in a hunter/scout archetype. While later editions kept the spellcasting abilities for traditions' sake if nothing else, over time the ranger has turned away from its Dunadain roots--instead of being wandering defenders of civilization, they've become mere hunters.

Fifth Edition D&D tries to return the rangers to their roots somewhat: "Far from the bustle of cities and towns, past the hedges that shelter the most distant farms from the terrors of the wild, amid the dense-packed trees of trackless forests and across wide and empty plains, rangers keep their unending watch" (PHB, p. 89). However, the best description I've ever found of what a ranger is supposed to be comes not from D&D, but from Swords & Wizardry Complete (p. 19):

You and your fellow Rangers are the inheritors of ancient scholarship, students of forgotten skills and lore passed on from teacher to student over the generations, preserving the legacy through times when the light of civilization wavered and dimmed. The Rangers retreated to the wilderness and the outlands long ago; they seldom visit the decadent, glittering cities, for these are places that have turned aside from much of the lore the Rangers protect. As a Ranger, you are well-versed in the subtle skills of the wilderness, and you are a dangerous opponent in battle. Moreover, when you reach higher level, your studies and understanding of ancient lore will have developed to the point where you can actually cast spells. You are a guardian of civilization and a protector of the weak, normally hunting the creatures of chaos in the wild places where they lurk. You take the battle directly to the enemy, in its very lair. 

A ranger in Newold is not simply a person who engages in the profession of a hunter, scout, or warden. There are plenty of fighters and unclassed humans with the Outlander background who fill those roles. Rangers are the scion of Kalavala and the Fallen North. Many trace their lines to the kings of Kalavala itself, but over the centuries they have adopted many lost children of other lands and even initiated a few non-humans into their lore. They are particularly close to the wood elves, and their ranks include many of half-elven blood, which has earned them the enmity of the Grey Riders and the Unseili.

The Rangers of the North are particularly vested in patrolling the Black Forests and into the edges of the Pohjola Hills, dwelling among the ruins of Kalavala that stretch from eastern Beldaroth to the Valley or Urlaen in the south to the Golden Land. However, the despoiling of Kalavala has carried its artifacts all over the known world, and the rangers can be found travelling in all of the lands surrounding the Cerianne and Elenion Seas seeking out and recovering their heritage. On such missions, they often travel disguised as mercenaries, merchants, or pilgrims.

Rumor has it that the law of the rangers pronounces the death penalty on anyone who possesses a Kalavalan artifact. While technically true, the penalty is rarely invoked. Upon finding someone with a Kalavalan artifact, they will always attempt to simply buy it back peacefully first. If that fails, they have no qualms in stealing the item (leaving behind some ancient Kalavalan gold coins in compensation). However, if the item has magic and the possessor is using it for evil purposes, the rangers have been known to kill where they see no other choice.

Nevertheless, their mysterious origins and motivations and their reputation for ruthlessness has led most civilized lands to either bar the rangers from their domains or to watch them very carefully when they appear. Even in lands where the rangers' help has been vital in the past, like Urlaen, Beldaroth, the Ossiri Marches, Umbria, and Westerlain, it is forbidden for more than three rangers to travel together at a time. In general, the rangers abide by these laws and travel openly in such lands despite the scowls and disdain it earns them from "civilized" folk. They live amidst the ruins of the past, only occasionally visiting outlying towns and villages, and keep their silent, thankless watch lest the evil that befell their ancient homeland destroy the good folk of the southern lands.