Spirit Folk

[M Placeholder]

Spirit Folk base stats -

Ability Score Increase – Your Wisdom increases by 2 and your dexterity increases by 1
Size – Spirit Folk weigh in the region of 120 pounds and stand around 5-6 feet tall. Your size is medium
Speed – You have a base speed of 30 feet
Darkvision – You have Darkvision out to 120ft

Mountain Spirit Folk -

Climb – You have a base climb speed of 30 feet
Avian Understanding – You can cast Speak With Animals to communicate with any birds once per long rest. Wisdom is your attribute for casting.
Sure Footed – You are proficient in Athletics and Acrobatics.
Language – You can speak Common and Sylvan

River Spirit Folk

Swim – You have a base swimming speed of 30 feet, and have advantage on one check to avoid underwater hazards once per short rest. Any equipment and items that you have on your person do not get wet.
Water Breathing – You are able to breathe water as easily as you can breathe air
Aquatic Understanding – You can cast Speak With Animals to communicate with any fish once per long rest
Fluvial Resistance - You have advantage on saving throws against spells with the word water in the name of the effect.
Languages – You can speak Aquan and Common.

Sea Spirit Folk

Swim – You have a base swimming speed of 30 feet, and have advantage on one check to avoid underwater hazards once per short rest. Any equipment and items that you have on your person do not get wet.
Water Breathing – You are able to breathe water as easily as you can breathe air
Tempest Insight – You are in tune with the changing winds and the tides. You are proficient in Nature, and you can make a Nature check (DC15) to predict the weather for the next 24 hours.
Fluvial Resistance - You have advantage on saving throws against spells and spell like effects with the word water in the name of the effect.
Languages – You can speak Aquan and Common.

Bamboo Spirit Folk

Animal Understanding – You can cast Speak With Animals to communicate with any birds once per long rest.
Trackless Step – You leave no trail for others to follow in the wild, and as a consequence, you cannot be tracked in the wild.
Child of the forest – You are proficient in Nature.
Earthen Resistance – You have advantage on saving throws against spells and spell like effects with the words earth, rock, stone or wood in the name of the effect.
Languages - You can speak Common and Sylvan

[PotatoGolem]

Low light vision no longer exists in 5e. Make it darkvision. Otgerwise, seems fine

[Ninja_Prawn]

Assuming you value the climb speed at +1 (which seems like an overestimate to me), yeah, it's 6 Musicus points.

Should be fine. May turn out to be underpowered if your campaign doesn't spend much time in mountain eyries.

[M Placeholder]

Thanks, I've changed the 60ft low light vision to Darkvision.

[M Placeholder]

Assuming you value the climb speed at +1 (which seems like an overestimate to me), yeah, it's 6 Musicus points.

Should be fine. May turn out to be underpowered if your campaign doesn't spend much time in mountain eyries.

Thanks. Its the Unapproachable East and there are a lot of mountains, so it should be fine.

Any thoughts on the others? I should have them in a nice document by the end of the week.

[Ninja_Prawn]

Well, Fluvial Resistance is a bit weird... The list of spells to which it applies is:

Control Water
Create Food and Water
Create or Destroy Water
Shape Water
Wall of Water
Water Breathing
Water Walk
Watery Sphere

Most of those are utility spells that don't really target creatures with hostile effects (bold indicates exceptions), meaning it's an extremely narrow ability. I would revise it to something broader but weaker.

The bamboo folk also look a bit powerful. Compared to the mountain version, they lose the climb speed and gain Earthen Resistance, Mask of the Wild and half of Pass Without Trace as an always-on trait. The abilities are just as solid, more numerous and have strong synergy. Maybe cut the Earthen Resistance? That would probably make things line up better.

For reference, Earthen Resistance spells:

Bones of the Earth
Conjure Woodland Beings
Earth Tremor
Earthbind
Earthquake
Erupting Earth
Flesh to Stone
Investiture of Stone
Magic Stone
Maximillian's Earthen Grasp
Meld into Stone
Mold Earth
Move Earth
Stone Shape
Stoneskin
Transmute Rock
Wall of Stone

That's pretty significant. Having resistance to all of these spells gives you a big leg-up against druids.

[M Placeholder]

Looked at the entries on the Spirit Folk in the Monstrous Compendium Kara-Tur Appendix, and they had 120ft infravision, so put the darkvision up to 120 feet. The River and the Sea Spirit Folk had a feature where nothing they possessed got wet when they swam, so added that feature to those subraces.

As for the Bamboo, removed the mask of the wild type feature from them.