Rather than waiting around to be in the right environment to work with, some rangers call upon the spirits of nature to change the immediate environment around them to suit their needs. These spirits help them create a natural aura that is useful both in battle and while exploring. Domainseekers tend to be travelers, choosing to explore new environments for the thrill of it rather than staying rooted in one place. Wherever they go, Domainseekers bring a little bit of something familiar with them.

The Domainseeker Ranger focuses on the favored terrain of the ranger, manipulating the environment around them to suit their needs both on and off the battlefield. While manifesting the power of nature as an aura, they apply the effects of their favored terrain on the world. This subclass is about movement and crowd control.

Natural Domain

At 3rd level, you can use a bonus action to call on the spirits of nature to shift the current environment in your favor, making it into your natural domain. When you do so, an aura extends 15 feet from you in every direction as a sphere, but not through total cover.

You gain the effects you would normally gain from your favored terrain while your domain is active. Any additional effects of your domain depend on the terrain you chose with the Natural Explorer feature, and the domain itself lasts for 10 minutes. Your domain has an effect that occurs when it activates, and you can activate the effect again on each of your turns as a bonus action. When you first activate your domain, choose a number of creatures equal to your Wisdom modifier that the aura will affect, marking them mystically. These creatures will experience the following effects when in your domain in addition to any additional effects provided by your terrain:

• Marked creatures that move into or start their turn in your domain have their movement speed halved as the area becomes difficult terrain for them.
• Marked creatures that attempt to make an opportunity attack against you do so with disadvantage.

You can activate your domain a number of times equal to your Wisdom modifier, and you regain all uses on a long rest. If your domain’s effects require a saving throw, the DC equals 8 + your proficiency bonus + your Wisdom modifier. It ends early if you are knocked unconscious or incapacitated. You can also deactivate your domain on your turn as a bonus action.

As you gain additional terrains from your Natural Explorer feature at 6th and 10th level, you can freely choose which terrain your domain will emulate, choosing one to express at a time. Switching between terrains counts towards the number of times you can activate your domain.

Arctic. When this effect is activated, choose Frostbite or Slip and Slide. If you choose Frostbite, all marked creatures within your domain must make a Constitution saving throw. On a failed save, the target takes 2 cold damage each as arctic spirits attempt to freeze them to the bone. This damage increases when you reach certain levels in this class, increasing to 3 at 5th level, 4 at 9th level, and 6 at 13th level. If you choose Slip and Slide, all marked creatures within your domain must make a Dexterity saving throw. On a failed save, the target becomes knocked prone as arctic spirits create ice to disrupt its footing.

Coast. When this effect is activated, you can choose between Carapace Armor or Ink Cloud. If you choose Carapace Armor, you gain 2 temporary hit points as coastal spirits fend off harm with a protective shell that surrounds you. The temporary hit points increase when you reach certain levels in this class, increasing to 3 at 5th level, 4 at 9th level, and 6 at 13th level. If you choose Ink Cloud, you can choose one marked creature within your domain. The target must make a Dexterity saving throw. The target is blinded on a failed save until the end of their next turn as coastal spirits blind them with ink.

Desert. When this effect is activated, you can choose between Dust Devil and Shrivel. If you choose Dust Devil, you can choose one marked creature within your domain. The target must make a Strength saving throw. On a failed save, the target is pushed 10 feet away from you in a straight line as desert spirits whip up a small dust devil to push them out. If you choose Shrivel, all marked creatures within your domain must make a Constitution saving throw. On a failed save, the target takes 2 fire damage each as desert spirits attempt to dry them out. This damage increases when you reach certain levels in this class, increasing to 3 at 5th level, 4 at 9th level, and 6 at 13th level. one marked creature within your domain.

Forest. When this effect is activated, you can choose between Hay Fever and Underbrush. If you choose Hay Fever, all marked creatures within your domain must make a Constitution saving throw. On a failed save, the target becomes incapacitated as forest spirits fill the air around it with pollen. Creatures that do not have eyes or creatures that do not need to breathe are immune to this effect, automatically passing their save. If you choose Underbrush, you can Hide as forest spirits obscure your form from others. When you are hidden from a marked creature while using this and miss it with a ranged weapon attack, making the attack doesn't reveal your position.

Grassland. When this effect is activated, you can choose between Crabgrass and Nettle. If you choose Crabgrass, you can choose one marked creature in your domain that you can see. The target must make a Dexterity saving throw. On a failed save, the target is restrained as grassland spirits entangle it, holding it in place. A creature restrained in this manner or one that can touch the creature can use its action to make a Strength check against your save DC. On a success, the target is freed. If you choose Nettle, marked creatures that hit you with an unarmed melee attack take an amount of piercing damage equal to your Wisdom modifier as grassland spirits protect you with thorny leaves.

Mountain. When this effect is activated, you can choose between Boulder and Landslide. If you choose Boulder, you can choose one marked creature within your domain. The target must take a Dexterity saving throw. On a failed save, the target takes an amount of bludgeoning damage equal to your Wisdom modifier. If you choose Landslide, all marked creatures within your domain must make a Dexterity saving throw. On a failed save, the target takes bludgeoning damage equal to your Wisdom modifier and gets pushed 10 feet away from you in a straight line.

Swamp. When this effect is activated, choose between Corrode and Quicksand. If you choose Corrode, all marked creatures within your domain must make a Constitution saving throw On a failed save, the target takes 2 acid damage as swamp spirits attempt to slowly digest it. This damage increases when you reach certain levels in this class, increasing to 3 at 5th level, 4 at 9th level, and 6 at 13th level. If you choose Quicksand, you can choose one marked creature within your domain. The target must make a Strength saving throw. On a failed save, the target becomes restrained as swamp spirits create quicksand around it. A creature restrained in this manner or one that can touch the creature can use its action to make a Strength check against your save DC. On a success, the target is freed.

Underdark. When this effect is activated, choose between Eerie Chill and Thunderous Echo. If you choose Eerie Chill, you can choose one marked creature within your domain. The target must make an Intelligence saving throw. On a failed save, the target is frightened until the end of its turn as cave spirits instill an instinctual fear of you within it. A creature frightened in this manner can use its action to make an Intelligence saving throw against your save DC. On a success, the creature is immune to the effect for 24 hours. If you choose Thunderous Echo, all creatures within your domain must make a Wisdom saving throw. On a failed save, the target is deafened until the end of its turn as cave spirits disrupt its senses of hearing. Creatures that do not rely on hearing to sense their environment are immune to this effect.

Natural Gift

At 7th level, you can manifest the power of your natural domain within yourself as well, augmenting your abilities. When your domain is activated, you gain one ability associated with your chosen terrain. This ability lasts as long as your domain is active.

Arctic. As an action, you can touch water and turn a 5-foot cube of it into ice, which melts after 1 minute. This action fails if a creature is in the cube.

Coast. You gain a swimming speed equal to your walking speed and can breathe underwater.

Desert. When you take the Disengage action, attacks against you are made with disadvantage.

Forest. You gain a climbing speed equal to your walking speed and can stick to walls provided you have at least one free hand.

Grassland. You gain an additional 30 feet to your walking speed.

Mountain. Your long jump is up to 25 feet and your high jump is up to 15 feet, with or without a running start.

Swamp. Your gain a number of temporary hit points equal to your Wisdom modifier + your proficiency bonus.

Underdark. You have blindsight with a range of 15 feet. Within that range, you can effectively see anything that isn't behind total cover, even if you're blinded or in darkness.

Domain Protection

At 11th level, you can manifest the power of your favored terrain even when it’s not active. Depending on your favored terrain, you gain resistance to a damage type determined by your favored terrain: arctic (cold), coast (lightning), desert (fire), forest (poison), grassland (poison), mountain (thunder), swamp (acid), or underdark (psychic). When you gain a level in this class, you can replace your resistance with another one provided it corresponds with one of your favored terrains.

Communal Domain

At 15th level, you’ve gained more control over your ability to channel the spirits of nature, allowing you to extend your natural boons to your allies. When you activate your domain, you can choose a number of creatures equal to your Wisdom modifier. A chosen creature reaps the benefits of the resistances you receive from Domain Protection when it is in your domain.