Rangers all are known to master surviving the rigors of natural environments and prove themselves the bane of various creatures, but might find themselves confounded by new enemies and new regions.  However, there are some special few that are true explorers of nature and can apply the skills and knowledge that most consider a specialty in order to overcome the adversity of fighting new foes in strange lands.  These rangers have learned to adapt to any terrain and any foe, taking their natural wisdom about the places they've been to master new challenges that present themselves throughout an adventure.  An adaptive Ranger can never be caught truly off guard, evolving old skills to deal with new experiences.  These rangers are known as "Adaptive Rangers", though none among their ranks would use the term to describe themselves, simply referring to themselves and each other as simply "Rangers".

Adaptive rangers are not an order or a discipline, and there is no title or organization among them.  They are simply rangers who have skills and mental flexibility to survive any journey and take on any battle, regardless of where fate may drag them.  There are some common themes among them, however.  Adaptive rangers are especially observant, and rarely distracted by the wonders one might encounter on an epic journey, simply relating each element to something much more mundane the ranger finds relevant.  This does not mean the ranger doesn't take joy in what surrounds them, but simply far more invested in understanding and participating in the natural world, rather than just passively observing.

Those who can be called Adaptive Rangers have a deeper understanding of the skills and abilities a ranger holds dear, gaining added benefits many do not when dealing with favored enemies and favored terrain.  Adaptive rangers do not consider what they do special in any way, but simply just what any other would do if they could focus clearly on that task at hand.  They do not seek to stand out, but to do the job of any ranger....just better.

Adaptive Ranger Spells

You can choose an additional spell from the Ranger Spell list of each spell level and they do not count against your spells known.  You always have these spells prepared.

Extra 1st Level Ranger Spell

Extra 1st Level Ranger Spell that is always prepared and doesn't count against spells known.

Extra 2nd Level Ranger Spell

Extra 2nd Level Ranger Spell that is always prepared and doesn't count against spells known.

Extra 3rd Level Ranger Spell

Extra 3rd Level Ranger Spell that is always prepared and doesn't count against spells known.

Extra 4th Level Ranger Spell

Extra 4th Level Ranger Spell that is always prepared and doesn't count against spells known.

Extra 5th Level Ranger Spell

Extra 5th Level Ranger Spell that is always prepared and doesn't count against spells known.

Focused Enemy

At 3rd level, you can study a new foe to gain advantage over them like a favored enemy and become more adept at fighting favored enemies.  After a period of study you can designate a type of creature as the enemy you are focused on, gaining the same benefits against them as if they were a favored enemy.  You do not learn that creature's language aside from perhaps a few phrases determined by an Intelligence check.  Making an enemy into a focused enemy requires at least either 3 hours of study with a live subject where the ranger can interact with the creature, a full day of study from witness accounts and stories where the ranger can ask questions and learn from another's experiences, or a week of study from written materials and more abstract methods.  You can have as many focused enemies as you do favored enemies, and may exchange a creature type for another after the appropriate study.  Dropping a creature type as a focused enemy removes the bonuses against them, and a new period of study is required to gain those advantages back later.  Furthermore, your understanding of favored enemies runs deeper, granting you advantage on Wisdom (Perception) and Wisdom (Insight) checks against them, and allowing you to do an additional 1D6 damage against them in combat.

Learn the Land

At 3rd level, you have a strong understanding of universal nature skills and can quickly understand a new environment, becoming as adept at surviving there as you would your favored terrain.  You gain proficiency in Intelligence (Nature) skill checks and gain a bonus to it equal to your Wisdom Modifier.  After being active in a new surroundings for a day you can apply your understanding of terrain with which you are familiar to it, gaining the benefits of your Natural Explorer ability as if it were your favored terrain.  Given the time to adapt you can become comfortable in almost any locale, even urban environments like cities.  Furthermore, you benefit for entering your favored terrain much sooner than normal and enjoy a deeper connection to that location, needing only ten minutes of travel to gain the benefits available through your Natural Explorer ability, and adding your Proficiency Bonus to an Intelligence or Wisdom check related to that terrain.

Conventional Wisdom

At 3rd level, you know what in your surroundings is consumable and what in your surroundings is toxic, based on an overall wisdom about the effects of what lies in nature.  Your overall understanding of the wilds has translated into a conventional wisdom about what in nature is safe to consume and what effects it may have, as well as what can be toxic and how it may be harmful.  You can apply this knowledge of effects into an understanding of health and the body, gaining proficiency in Wisdom (Medicine) skill checks.

Natural Awareness

At 7th level, you are especially aware of your natural surroundings, gaining double Proficiency Bonus on Intelligence (Nature), Wisdom (Perception), and Wisdom (Survival) skill checks.  The wilds have taught you that those that lose their focus tend to meet a tragic end, and so you've become especially keen on perceiving your surroundings, the threats contained within, and what it takes to survive them.  Catching you off-guard is a terribly difficult endeavor, and you are ever aware of what to do in order to keep safe.

Guerrilla Tactics

At 11th level, you gain Advantage on Dexterity (Stealth) checks when using your Hide in Plain Sight ability, and retain that Advantage on subsequent checks after moving.  When creating camouflage to use your Hide in Plain Sight ability you can craft it to more naturally fit the environment you are in, granting you Advantage on Dexterity (Stealth) checks to hide in that environment that lasts even if your initial attempt to hide fails, you take an action, you take a reaction, you move from your position, or anything else that would cause you to lose the +10 bonus that ability grants.  You can move with stealth at full speed and you retain Advantage on Dexterity (Stealth) checks until the camouflage is removed, or you enter a completely new environment that no longer matches the camouflage.

Master Explorer

At 15th level, you can adapt to any terrain, including truly outlandish places like other planes or new planets, allowing you to use your Learn the Land and Conventional Wisdom abilities anywhere. Your wisdom when it comes to understanding nature can apply to truly any place you can reach, and cannot be confounded by even utterly foreign locales, allowing you to find a way to thrive where most would simply become lost and perish.  You can apply the same benefits of a favored terrain and your Conventional Wisdom ability to any place, no matter how bizarre, by using your Learn the Land ability to understand your local environment.