There are a lot of things I like about this product, but I think it could use some expansion or clarification on certain things.

What I liked:

• Good organization, very user friendly, the references and player questionnaire at the back are great;
• Abstract supplies and being able to use abstract supplies to pull out a needed item in the middle of the adventure is a great idea (but see below);
• Character death and becoming Cold-Blooded is a great idea and mechanic and one I'm adopting in my Frostmaiden campaign right away;
• Three new monsters are very good and tie in very well into the type of horror that Frostmaiden is going for. I'm definitely using them, since most of the new monsters in Frostmaiden are rather boring.

What I didn't like:

• Abstract supplies sounds great in theory but other systems (like Five Torches Deep) did it better. What happens if a player character has negative strength, or strength of zero, how many uses of Adventurer's Pack do they get? For that matter, isn't the amount of uses of Adventurer's Pack a bit ludicrous? A character with a Str modifier of 1 can have two uses of a pack? So that kind of implies that they can only carry two rations? That seems quite silly to me. The number of uses of Adventurer's Pack needs to be upped or based off of something other than Str modifier (maybe it should just equal the character's Str score);
• Related problem with the abstract supplies and Adventurer's Pack: what about mounts and goliaths and magic items like Handy Haversak or Bag of Holding, or other ways to carry additional weight? I think a bit more thought could go into this;
• The optional long-rest mechanic is too punishing. I played in a game that homebrewed a very similar rule (clearly inspired by Darkest Dungeon) and all it did was punish the spellcasters and made the game a lot less fun. In Frostmaiden, especially Chapter 2 and beyond, it's often difficult or even flat out impossible to return back to a town or it could take upwards of a week to do so. I can see this optional mechanic really breaking the module and players' enjoyment as soon as they get into serious wilderness exploration.
• I like the idea of PCs succumbing to vice and madness if they fail to get a proper rest or indulge a little too much during rest, but the optional rule presented here just wasn't for me personally. Make a new character because your existing character is missing on a bender? I think a lot of players would have a major problem with this. I'd use short-term madness mechanics from DMG instead;
• This is purely subjective and YMMV but the product could use some additional proofreading and the author's tone isn't something I personally liked. But again - different strokes for different folks.

There are many excellent ideas in this book that I will definitely mine and tinker around with for my Frostmaiden game. I recommend this book for the new monsters and for these ideas, but personally I don't see myself adopting the new systems and optional rules from this book wholesale - they will require significant tinkering before I do. I don't regret purchasing this product however.

This pulls of a great middle ground between simplicity and tracking. It also assumes that PCs are good at what they do, which is a fair place to start. I also enjoy that it helps add a little oomph to Strength which is generally one of the more ignored stats in the current edition.

My next tier 1 campaign will be using this when in hazardous environments.

I'm not American, please accepts my poor writing.

I like more difficult long rest. It makes exploration seriously unchanagable. One day, PC strugle cliff, falling stone, slip, and then long rest! All clear!

I don't like capacity of Adventurer's gear. Twice their Strength modifier is too restricted to Spellcaster. For example, Strength 10 Wizard can't take any Adventurere's gear! I personally use half of Strength abilty score + size.

An excellent supplement if you're looking to inject a little horror or survivalism into your games, and the "Never Unprepared" streamlines inventory management. Overall, it's pretty good.

This supplement is both easy to learn and to implement to your game of Rime of the Frostmaiden. It brings up the themes of cold, horror, and dealing with these problems on your adventures, which the adventure itself unfortunately failed to do properly.

The author weaves some of the mechanics of Dungeon World and Blades in the Dark into 5E, and in my opinion, it only helps, because ultimately I think 5E is a game about heroic exploits; adventures like RotF need some of the rules rewritten and repurposed, so the game itself could support the themes of horror. If you use Coldblood, you don't need to do it yourself.

Never Unprepared mechanic GREATLY cuts down discussions about what to buy which, in the case of survival themes presented in RotF, may result in analysis paralysis of the whole table. Do we need rations for 20 days? How many torches? Do we need some extra warm clothes in the case we meet some pour soul out in the wild? Climbing gear is pretty heavy, will we come across vertical surfaces at all today? The list of such questions goes on, and on, and on. This chapter boldly states your characters are prepared at all times, still keeping 5th edition's heroic themes but still making it about survival.

And then it takes a dark turn; again, for the good of it.

Heroes need to keep themselves sane: if they simply return from their marches, sleep in the tavern and ready to go again, it breaks the immersion and harms the survival theme. Characters should be GLAD to see other souls, they should be OBLIGED to pray to their gods, they should NEED to relieve some of the stress by partaking in activities like gambling or simply drunken story sharing. It will help with building of your shared story and serve as a much-needed break for both characters and players.

Taking Watch action, which the author took from Dungeon World, helps you streamline camping in the wild. Something is always out there, and this rolls helps you determine if your party is ready to meet it.

The chapter about death is easily my favourite one. It makes death something less permanent and more story-building. It helps you to define the madness of Auril more. It helps you to describe the horror of the North way better. But also it can help fighting the anxiety of losing your character forever if you are a player like me: I always fear losing a character I've invested time into. I want their death to be heroic, not just because of a bad roll. This mechanic helps people like me to dictate when my character goes into the blizzard forever.

Embrace the change. Don't lose hope. Paint it black.