Winter of Atom has a good story, optional survival mechanics, the beginnings of a settlement/reputation system, and a few pages that make combat encounters clearer, but I bought this book primarily for the new Gen 3 Synth player character background, given their importance in the world of Fallout 4. There are a total of 3 new backgrounds in Winter of Atom -- Gen 3 Synth, Protectron, and Child of Atom.

When the new Settler's Guide Book was released a few days ago, I quickly purchased it for the same reason -- the new character backgrounds, weapons, and craftable items to add to the core game -- only to find that it, too, contained the Gen 3 Synth and Protectron backgrounds, settlements/reputation covered in greater depth, and even the Salvaged Assaultron Head weapon stats (one of the big selling points of the Rust Devils content).

If, like me, you are mainly interested in system additions (characters, weapons, perks, etc) then my recommendation would be to skip this title and get the new Settler's Guide Book instead. I wish Modiphius provided more detail on their roadmap so we could get an idea of overlap within the published and upcoming Fallout 2d20 books -- it's frustrating to pay for the same content twice. Changing the statement "Create characters with new origin options: Generation 3 Synths, Protectrons, and Children of Atom" in the product description to "Winter of Atom contains previews of the Gen 3 Synth and Protectron backgrounds from the upcoming The Settler's Guide Book" would have let me know that I could wait for the next book.

This might be one of the best expansions that Modiphius has ever released. It builds on the base Fallout RPG system in interesting and flavorful ways, and the core campaign of the book is an amazing read. It successfully builds on the Commonwealth setting without leaning too hard on the big factions of Fallout 4, giving the players, minor characters from Fallout 4, and the new NPC's introduced a chance to shine. The new NPC's and settlements are the real meat of this book, and Modiphius knocked it out of the park. Information is provided in clear and concise ways that makes it easy reading for me as GM, and they hit the sweet spot of providing enough details that I feel I understand characters and places really well while also leaving room for me to introduce new elements that I'd prefer or that result from player actions. The advice they offer for everything from the best way to describe horror elements depending on your audience to the "fallout" from the player's actions during quests is really great.

If I had a quibble with thos book it's that it does leave some important parts of the Commonwealth out. Most notably Bunker Hill is only mentioned in passing, which seems odd for a story that deals a lot with supplies in the Commonwealth during winter. But this is a minor quibble for me, and the books is overall well worth its price of a little over twenty bucks.