Okay, Icewind Dale: Rime of the Frostmaiden and its lack of cold themed spells (plural) got me thinking about what classes should get cold spells, and what subclasses could be cold themed. I've made cold-focused subclasses for the druid, paladin, ranger, sorcerer, and warlock classes (which will appear in later threads and be linked here) as well as multiple cold spells. However, as there are some gods of the winter and cold, I also felt the need to create a cleric domain devoted to these deities. Please give your thoughts and feedback down below on the spells and domain. 

Here's the Frost Domain Cleric. I made some homebrew cold spells I made they and other classes/homebrew subclasses get. 

Gods of frost - such as Auril, Thrym, Khione, Boreas, Aeolus, Persephone, and other such deities either control the change of summer to winter, teach dwellers of northern settlements how to survive harsh winters, or have some connection to frosty and cold magic. 

More sinister gods of this domain demand sacrifices, veneration, and obedience in exchange for their lives, while more benevolent frost deities willingly aid towns in their struggle for survival in the winter and use their powers for good. Most deities of this domain are different from the deities of other domains, as winter is a short season in most of the world, and the sections of the planet where cold powers are stronger are typically small regions of the world. Though, in these regions, worship of these deities can be a matter of life or death. Due to this, deities of this domain are typically lesser deities mostly revered near the poles of the world, or this domain a just a small fragment of the portfolio of a god of weather, nature, and cold winds. 

Because of the fact that most deities of this domain have limited portfolios have few followers, the worshippers they do have are often more devout than the typical follower of a different deity. This can be very bad news for settlements of the far north and south, making sacrifices for these deities a common practice. Whether or not clerics devoted to this domain are evil, they do get access to power over cold weather and ice, which they can use for good or evil.

Domain Spells

You gain domain spells at the cleric levels listed in the Frost Domain Spells table. See the Divine Domain class feature for how domain spells work.

Frost Domain Spells

Bonus Proficiencies

At level 1, you gain proficiency with martial weapons and a skill of your choice from the list of following skills: Animal Handling, Insight, Perception, or Survival. Your proficiency bonus is doubled for any ability check that you make for the skill you chose. 

Call of Frost

Also at level 1, you gain the ability to harness the powers of ice. Choose one cantrip that deals cold damage from any spell list. You know and can cast that cantrip, not counting against the amount of cantrips you can know, and it counts as a cleric cantrip for you.

Channel Divinity: Frigid Mark

Starting at 2nd level, you can choose one creature that you hit with a melee attack to be covered in paralyzing frost, expending a Channel Divinity. 

Until the end of your next turn, this creature cannot move or be moved by any means except teleportation, and they gain vulnerability to bludgeoning, cold, and fire damage. If they have immunity to one of those damage types, they do not become vulnerable to that damage type. 

Lethargic Frost

At 6th level, you can harness your powers of frost to protect yourself from cold and momentarily slow enemies. You gain resistance to cold damage. 

Additionally, when a creature within 30 feet of you that you can see takes a bonus action or reaction, you can use your reaction to force them to expend the triggering action, but not gain any of its effects. You can use this feature an amount of times equal to your Wisdom modifier (minimum of once). You regain all expended uses when you finish a long rest. 

Divine Strike

At 8th level, you gain the ability to infuse your weapon strikes with divine cold energy. Once on each of your turns when you hit a creature with a weapon attack, you can cause the attack to deal an extra 1d8 cold damage to the target. When you reach 14th level, the extra damage increases to 2d8.

Herald of Ice and Snow

At 17th level, your power over cold increases greatly, granting you the following:

• You gain immunity to cold damage. 
• Choose one spell from the following levels; 6th, 7th, 8th, and 9th level that deals cold damage. You automatically prepare those spells, and they become cleric spells for you. 

Here's the spells they get: 

Blizzard

Frozen Strike 

Ice Blade

Ice Cube

Thanks for reading!

I'll get to this Tomorrow, it's almost 10 my time, and I am TIRED. A first glance, seems very good, and INCREDIBLY thematic. I'll be happy to look at it tomorrow.

Totally fine. Thanks in advance! 

(I don't get online on Sundays, so I'm afraid I'll have to respond to your reviews on Monday.)

Okay, Frost Domain. 

• Thematic-ness: Great flavor, seems like it would work GREAT in a RotF campaign.
• Spells: Lots of Ice Spells, which makes sense for the subclass. Small note: You might want to add a description of what Ice Fingers does, as not everybody has RotF. A similar thing applies to any XGtE spells, but I feel like more people have that book, so its fine.
• Bonus Profs: Martial Weapons, okay. Also, a fun Thematic Proficiency. Not sure about Insight, but I think its fine otherwise.
• Call of Frost: Cold dealing Cantrip, which is pretty cool. Puns aside, Flavorful, makes sense. However, there are only two Cantrips that deal Cold Damage (Frostbite and Ray of Frost). Keep that in mind, maybe add some Homebrew Cold-Dealing Cantrips, or allow them to choose from some more Cantrips. Maybe add acclimation to Cold Climates?
• Frigid Mark: Paralyzes and gives Vulnerability to Bludgeoning, Fire, and Cold Damage. Doesn't affect Immunity. Honestly, it feels a little Underpowered, especially compared to Path to the Grave, which gives a similar effect. Maybe, when a creature has an Immunity to one of the Damage types, you ignore the Immunity? Still would be less powerful than Path, but coupled with the Paralyzation, it would probably be fine.
• Lethargic Frost: Resistance to Cold, makes sense. Also, allows you to negate the effects of a Reaction or Bonus Action. Which is really cool. I don't think that I've seen this type of feature before!
• Divine Strike: This makes sense. Coupled with the Martial Weapons, and the Channel Divinity, and the Spell List, this subclass can deal quite a bit of damage.
• Herald of Ice and Snow: Immunity to Cold Damage, that's fair, and an ability similar to the Arcana Domain capstone. However, the Spells have to deal Cold Damage. There are quite a few 6th Level Spells that deal Cold Damage, but for 7th, there's only Prismatic Spray, 8th is only Illusory Dragon, and 9th is only Prismatic Wall or Storm of Vengeance. Similar thoughts to Call of Frost, maybe add some Homebrew, or expand the possible Spells.

Overall, great class, seems pretty balanced.

Quote from MandosMindos>>

Okay, Frost Domain. 

• Thematic-ness: Great flavor, seems like it would work GREAT in a RotF campaign.

It would fit the theme of RotF, but I don't know how well it would work, as they'd probably worship Auril and focus on cold damage, which is very commonly resisted/immune to in this adventure. 

• Spells: Lots of Ice Spells, which makes sense for the subclass. Small note: You might want to add a description of what Ice Fingers does, as not everybody has RotF. A similar thing applies to any XGtE spells, but I feel like more people have that book, so its fine.

It's basically just a cold damaging Burning Hands, but is a Con save and 2d8 damage, not 3d6. 

• Call of Frost: Cold dealing Cantrip, which is pretty cool. Puns aside, Flavorful, makes sense. However, there are only two Cantrips that deal Cold Damage (Frostbite and Ray of Frost). Keep that in mind, maybe add some Homebrew Cold-Dealing Cantrips, or allow them to choose from some more Cantrips. Maybe add acclimation to Cold Climates?

I've created some homebrew cold cantrips. The first is Blue-Frost Blade, which is in this thread, the second is Snow Flurry, basically a cold version of Create Bonfire, and Icicle, which is a cold version of Fire Bolt. 

• Frigid Mark: Paralyzes and gives Vulnerability to Bludgeoning, Fire, and Cold Damage. Doesn't affect Immunity. Honestly, it feels a little Underpowered, especially compared to Path to the Grave, which gives a similar effect. Maybe, when a creature has an Immunity to one of the Damage types, you ignore the Immunity? Still would be less powerful than Path, but coupled with the Paralyzation, it would probably be fine.

I don't know. Maybe I could just change it to the Paralyzed condition?

• Lethargic Frost: Resistance to Cold, makes sense. Also, allows you to negate the effects of a Reaction or Bonus Action. Which is really cool. I don't think that I've seen this type of feature before!

I don't think there's really anything like it in the game yet, so I thought it would be a cool thematic feature. 

• Divine Strike: This makes sense. Coupled with the Martial Weapons, and the Channel Divinity, and the Spell List, this subclass can deal quite a bit of damage.

(Especially when they use my Blue Frost Blade cantrip.)

• Herald of Ice and Snow: Immunity to Cold Damage, that's fair, and an ability similar to the Arcana Domain capstone. However, the Spells have to deal Cold Damage. There are quite a few 6th Level Spells that deal Cold Damage, but for 7th, there's only Prismatic Spray, 8th is only Illusory Dragon, and 9th is only Prismatic Wall or Storm of Vengeance. Similar thoughts to Call of Frost, maybe add some Homebrew, or expand the possible Spells.

I've created a few other cold spells, which I should probably put on this website soon. The 7th level ones are Growing Snowball (similar to delayed blast fireball) and Snow Storm (cold damaging fire storm). There's also the 8th level spell "Cloud of Winter," which is basically a cold damaging incendiary cloud. I have only made one 9th level cold spell so far, called Glacier, which is similar to a cold-damaging meteor swarm that can summon a huge glacier to destroy towns. 

Thanks!

Very cool. Maybe a bit op? Call of the frost is very good, and double proficiency is also good for level 1. Lethargic frost is very cool, but possibly op.

Quote from WarlockThatSlaysDragons >>

Very cool. Maybe a bit op? Call of the frost is very good, and double proficiency is also good for level 1. Lethargic frost is very cool, but possibly op.

I don't think Lethargic Frost is OP, especially as it is limited to Wisdom modifier uses per long rest, and requires your reaction to stop a reaction. For the subclass's balance, I'm not sure. I'll have to get more feedback on what could be problematic. Thanks!

this is what i needed, been looking for something like this for ages.  keep the good work

Alright I really like it! Especially the spells. I think Lethargic Frost is #1 quite powerful, and #2 gonna slow down the game though. I don't mind it being quite powerful as it isn't OP, although if a player started asking every dang turn if an enemy uses their bonus action, which will slow down the game and give the DM a headache.