Jungle terrain), fortified encampments (Desert), observation platforms (Mountains), floating citadels (Swamp and Aquatic), and ice towers (Arctic).
Perhaps the ranger's most interesting ability is the chance to attract unusual followers. Unlike fighters and other character classes that acquire followers, the ranger's followers include animals and magical creatures as well as humans and demihumans. In fact, it's possible that all of a ranger's followers may be animals, which can result in unexpected benefits (strangers aren't as likely to mess with a ranger accompanied by a wolf pack) as well as unforeseen complications (ever try getting a room at an inn with a bear trotting behind you?).
Humans and demihumans (and magical creatures) are drawn to a ranger because of his sterling reputation. They serve as followers out of loyalty and respect, remaining true to the ranger so long as he treats them decently. In this way, such followers are different from normal hirelings and mercenaries who serve for pay.
The motivations of animal followers are less obvious. Animals have no conception of what constitutes a reputation, sterling or otherwise. Instead, animals bond to rangers by instinct. The nature of this bond lies somewhere between the relationship of an infant animal and its parent (picture a baby duck contentedly swimming behind its mother), and a master and his pet (think of a dog's affection for the person who provides him with companionship). If the ranger honors the bond, the follower will often remain loyal for its entire life.
It's important to keep in mind that this bond has no magical basis. The follower stays with a ranger of its own volition, not from some supernatural compulsion, and may leave if conditions become intolerable. Likewise, a ranger doesn't control the actions of his followers, though he may instruct human followers to carry out specific functions, and train animal followers to perform various tricks and tasks.
It's strictly up to the Dungeon Master to determine when a ranger receives his followers, how many he's entitled to, and the circumstances under which they appear. Though the player is free to express his preferences, the DM has the final word.
As soon as a ranger reaches 10th level, the DM secretly rolls 2d6. The result indicates the maximum number of followers the ranger will receive over the course of his career. This roll is made only once, and the number is never revealed to the player. The DM should make a note of the number on a sheet of paper; he can use the same sheet to keep track of the followers as the ranger receives them to make sure he doesn't exceed his allotment. The player should also keep track of his ranger's followers; the record sheets at the end of this book are designed for this purpose.